diff --git a/.gitmodules b/.gitmodules
index e95e06940ca..cbb9898d82c 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -22,9 +22,6 @@
 [submodule "src/support/opengles/rust-opengles"]
 	path = src/support/opengles/rust-opengles
 	url = https://github.com/mozilla-servo/rust-opengles.git
-[submodule "src/support/glut/rust-glut"]
-	path = src/support/glut/rust-glut
-	url = https://github.com/mozilla-servo/rust-glut.git
 [submodule "src/support/layers/rust-layers"]
 	path = src/support/layers/rust-layers
 	url = https://github.com/mozilla-servo/rust-layers.git
diff --git a/Makefile.in b/Makefile.in
index 5d136a17fc7..e64ac6a1f8e 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -29,7 +29,7 @@ B := $(CFG_BUILD_DIR)
 
 MKFILE_DEPS := config.stamp $(call rwildcard,$(S)mk/,*)
 
-CFG_RUSTC_FLAGS := $(RUSTFLAGS) -A default_methods
+CFG_RUSTC_FLAGS := $(RUSTFLAGS)
 
 ifdef CFG_DISABLE_OPTIMIZE
   $(info cfg: disabling rustc optimization (CFG_DISABLE_OPTIMIZE))
@@ -235,23 +235,23 @@ all: src/compiler/rust/rust-auto-clean-stamp servo package
 
 $(DONE_util):	$(DEPS_util)
 	@$(call E, compile: $@)
-	$(Q)$(RUSTC) $(RFLAGS_util) -o $@ $< && touch $@
+	$(Q)$(RUSTC) $(RFLAGS_util) --out-dir src/components/util $< && touch $@
 
 $(DONE_net):	$(DEPS_net)
 	@$(call E, compile: $@)
-	$(Q)$(RUSTC) $(RFLAGS_net) -o $@ $< && touch $@
+	$(Q)$(RUSTC) $(RFLAGS_net) --out-dir src/components/net $< && touch $@
 
 $(DONE_msg):	$(DEPS_msg)
 	@$(call E, compile: $@)
-	$(Q)$(RUSTC) $(RFLAGS_msg) -o $@ $< && touch $@
+	$(Q)$(RUSTC) $(RFLAGS_msg) --out-dir src/components/msg $< && touch $@
 
 $(DONE_gfx):	$(DEPS_gfx)
 	@$(call E, compile: $@)
-	$(Q)$(RUSTC) $(RFLAGS_gfx) -o $@ $< && touch $@
+	$(Q)$(RUSTC) $(RFLAGS_gfx) --out-dir src/components/gfx $< && touch $@
 
 $(DONE_script):	$(DEPS_script)
 	@$(call E, compile: $@)
-	$(Q)$(RUSTC) $(RFLAGS_script) -o $@ $< && touch $@
+	$(Q)$(RUSTC) $(RFLAGS_script) --out-dir src/components/script $< && touch $@
 
 BINDINGS_SRC = $(S)/src/components/script/dom/bindings/codegen
 
diff --git a/configure b/configure
index f0c24ba25e6..88f580db82c 100755
--- a/configure
+++ b/configure
@@ -403,11 +403,9 @@ CFG_SUBMODULES="\
     support/css/rust-css \
     support/css/rust-cssparser \
     support/geom/rust-geom \
-    support/glut/rust-glut \
     support/glfw/glfw \
     support/glfw/glfw-rs \
     support/harfbuzz/rust-harfbuzz \
-    support/http-client/rust-http-client \
     support/hubbub/libhubbub \
     support/hubbub/rust-hubbub \
     support/layers/rust-layers \
diff --git a/mk/sub.mk b/mk/sub.mk
index 79f67e72954..38d748d9597 100644
--- a/mk/sub.mk
+++ b/mk/sub.mk
@@ -51,10 +51,6 @@ DEPS_glfw-rs += \
 	glfw \
 	$(NULL)
 
-DEPS_rust-glut += \
-	rust-opengles \
-	$(NULL)
-
 DEPS_rust-layers += \
 	rust-geom \
 	rust-opengles \
@@ -143,10 +139,6 @@ DEPS_rust-layers += \
 	rust-cocoa \
 	$(NULL)
 
-DEPS_rust-glut += \
-    rust-cocoa \
-    $(NULL)
-
 endif
 
 ifeq ($(CFG_OSTYPE),unknown-linux-gnu)
diff --git a/src/compiler/rust b/src/compiler/rust
index 5aa0ca9b2eb..0a677bcf6e3 160000
--- a/src/compiler/rust
+++ b/src/compiler/rust
@@ -1 +1 @@
-Subproject commit 5aa0ca9b2eb28166d9ab2e86557a5b1f84230b46
+Subproject commit 0a677bcf6e359f6f013a7e580ef467b5f389e5b7
diff --git a/src/compiler/rust-auto-clean-trigger b/src/compiler/rust-auto-clean-trigger
index 0ca4dcbb9d6..97ca03fb5ac 100644
--- a/src/compiler/rust-auto-clean-trigger
+++ b/src/compiler/rust-auto-clean-trigger
@@ -1,4 +1,4 @@
 # If this file is modified, then rust will be forcibly cleaned and then rebuilt.
 # The actual contents of this file do not matter, but to trigger a change on the
 # build bots then the contents should be changed so git updates the mtime.
-2013-07-09
+2013-08-15
diff --git a/src/components/gfx/display_list.rs b/src/components/gfx/display_list.rs
index 3c220974b9b..8a5bb04d7a4 100644
--- a/src/components/gfx/display_list.rs
+++ b/src/components/gfx/display_list.rs
@@ -23,7 +23,7 @@ use std::cast::transmute_region;
 use geom::{Point2D, Rect, Size2D, SideOffsets2D};
 use servo_net::image::base::Image;
 use servo_util::range::Range;
-use extra::arc::ARC;
+use extra::arc::Arc;
 
 /// A list of rendering operations to be performed.
 pub struct DisplayList<E> {
@@ -48,7 +48,7 @@ impl<E> DisplayList<E> {
     /// Draws the display list into the given render context.
     pub fn draw_into_context(&self, render_context: &RenderContext) {
         debug!("Beginning display list.");
-        for self.list.iter().advance |item| {
+        for item in self.list.iter() {
             // FIXME(Issue #150): crashes
             //debug!("drawing %?", *item);
             item.draw_into_context(render_context)
@@ -93,7 +93,7 @@ pub struct TextDisplayItem<E> {
 /// Renders an image.
 pub struct ImageDisplayItem<E> {
     base: BaseDisplayItem<E>,
-    image: ARC<~Image>,
+    image: Arc<~Image>,
 }
 
 /// Renders a border.
@@ -156,7 +156,7 @@ impl<E> DisplayItem<E> {
         }
     }
 
-    fn base<'a>(&'a self) -> &'a BaseDisplayItem<E> {
+    pub fn base<'a>(&'a self) -> &'a BaseDisplayItem<E> {
         // FIXME(tkuehn): Workaround for Rust region bug.
         unsafe {
             match *self {
@@ -168,7 +168,7 @@ impl<E> DisplayItem<E> {
         }
     }
 
-    fn bounds(&self) -> Rect<Au> {
+    pub fn bounds(&self) -> Rect<Au> {
         self.base().bounds
     }
 }
diff --git a/src/components/gfx/font.rs b/src/components/gfx/font.rs
index 7f4bddd7805..c8b2680dbfb 100644
--- a/src/components/gfx/font.rs
+++ b/src/components/gfx/font.rs
@@ -10,7 +10,6 @@ use platform::font::{FontHandle, FontTable};
 use render_context::RenderContext;
 use servo_util::range::Range;
 use std::cast;
-use std::result;
 use std::ptr;
 use std::str;
 use std::vec;
@@ -18,7 +17,7 @@ use servo_util::cache::{Cache, HashCache};
 use text::glyph::{GlyphStore, GlyphIndex};
 use text::shaping::ShaperMethods;
 use text::{Shaper, TextRun};
-use extra::arc::ARC;
+use extra::arc::Arc;
 
 use azure::{AzFloat, AzScaledFontRef};
 use azure::scaled_font::ScaledFont;
@@ -58,12 +57,12 @@ pub type FractionalPixel = float;
 
 pub type FontTableTag = u32;
 
-trait FontTableTagConversions {
-    pub fn tag_to_str(&self) -> ~str;
+pub trait FontTableTagConversions {
+    fn tag_to_str(&self) -> ~str;
 }
 
 impl FontTableTagConversions for FontTableTag {
-    pub fn tag_to_str(&self) -> ~str {
+    fn tag_to_str(&self) -> ~str {
         unsafe {
             let reversed = str::raw::from_buf_len(cast::transmute(self), 4);
             return str::from_chars([reversed.char_at(3),
@@ -183,7 +182,7 @@ impl FontGroup {
     pub fn new(families: @str, style: &UsedFontStyle, fonts: ~[@mut Font]) -> FontGroup {
         FontGroup {
             families: families,
-            style: copy *style,
+            style: (*style).clone(),
             fonts: fonts,
         }
     }
@@ -240,7 +239,7 @@ pub struct Font {
     metrics: FontMetrics,
     backend: BackendType,
     profiler_chan: ProfilerChan,
-    shape_cache: HashCache<~str, ARC<GlyphStore>>,
+    shape_cache: HashCache<~str, Arc<GlyphStore>>,
 }
 
 impl Font {
@@ -252,9 +251,9 @@ impl Font {
             -> Result<@mut Font, ()> {
         let handle = FontHandleMethods::new_from_buffer(&ctx.handle, buffer, style);
         let handle: FontHandle = if handle.is_ok() {
-            result::unwrap(handle)
+            handle.unwrap()
         } else {
-            return Err(handle.get_err());
+            return Err(handle.unwrap_err());
         };
         
         let metrics = handle.get_metrics();
@@ -264,7 +263,7 @@ impl Font {
             handle: handle,
             azure_font: None,
             shaper: None,
-            style: copy *style,
+            style: (*style).clone(),
             metrics: metrics,
             backend: backend,
             profiler_chan: profiler_chan,
@@ -281,7 +280,7 @@ impl Font {
             handle: handle,
             azure_font: None,
             shaper: None,
-            style: copy *style,
+            style: (*style).clone(),
             metrics: metrics,
             backend: backend,
             profiler_chan: profiler_chan,
@@ -302,7 +301,7 @@ impl Font {
         return Ok(Font::new_from_adopted_handle(fctx, styled_handle, style, backend, profiler_chan));
     }
 
-    priv fn get_shaper(@mut self) -> @Shaper {
+    fn get_shaper(@mut self) -> @Shaper {
         // fast path: already created a shaper
         match self.shaper {
             Some(shaper) => { return shaper; },
@@ -333,7 +332,7 @@ impl Font {
     // TODO: this should return a borrowed pointer, but I can't figure
     // out why borrowck doesn't like my implementation.
 
-    priv fn get_azure_font(&mut self) -> AzScaledFontRef {
+    fn get_azure_font(&mut self) -> AzScaledFontRef {
         // fast path: we've already created the azure font resource
         match self.azure_font {
             Some(ref azfont) => return azfont.get_ref(),
@@ -347,14 +346,14 @@ impl Font {
     }
 
     #[cfg(target_os="macos")]
-    priv fn create_azure_font(&mut self) -> ScaledFont {
+    fn create_azure_font(&mut self) -> ScaledFont {
         let cg_font = self.handle.get_CGFont();
         let size = self.style.pt_size as AzFloat;
         ScaledFont::new(self.backend, &cg_font, size)
     }
 
     #[cfg(target_os="linux")]
-    priv fn create_azure_font(&self) -> ScaledFont {
+    fn create_azure_font(&self) -> ScaledFont {
         let freetype_font = self.handle.face;
         let size = self.style.pt_size as AzFloat;
         ScaledFont::new(self.backend, freetype_font, size)
@@ -387,14 +386,14 @@ impl Font {
             fields: 0x0200 as uint16_t
         };
 
-        let mut origin = copy baseline_origin;
+        let mut origin = baseline_origin.clone();
         let mut azglyphs = ~[];
         azglyphs.reserve(range.length());
 
-        for run.iter_slices_for_range(range) |glyphs, _offset, slice_range| {
-            for glyphs.iter_glyphs_for_char_range(slice_range) |_i, glyph| {
-                let glyph_advance = glyph.advance_();
-                let glyph_offset = glyph.offset().get_or_default(Au::zero_point());
+        for (glyphs, _offset, slice_range) in run.iter_slices_for_range(range) {
+            for (_i, glyph) in glyphs.iter_glyphs_for_char_range(&slice_range) {
+                let glyph_advance = glyph.advance();
+                let glyph_offset = glyph.offset().unwrap_or_default(Au::zero_point());
 
                 let azglyph = struct__AzGlyph {
                     mIndex: glyph.index() as uint32_t,
@@ -431,9 +430,9 @@ impl Font {
         // TODO(Issue #199): alter advance direction for RTL
         // TODO(Issue #98): using inter-char and inter-word spacing settings  when measuring text
         let mut advance = Au(0);
-        for run.iter_slices_for_range(range) |glyphs, _offset, slice_range| {
-            for glyphs.iter_glyphs_for_char_range(slice_range) |_i, glyph| {
-                advance = advance + glyph.advance_();
+        for (glyphs, _offset, slice_range) in run.iter_slices_for_range(range) {
+            for (_i, glyph) in glyphs.iter_glyphs_for_char_range(&slice_range) {
+                advance = advance + glyph.advance();
             }
         }
         RunMetrics::new(advance, self.metrics.ascent, self.metrics.descent)
@@ -444,25 +443,25 @@ impl Font {
                                   slice_range: &Range)
                                   -> RunMetrics {
         let mut advance = Au(0);
-        for glyphs.iter_glyphs_for_char_range(slice_range) |_i, glyph| {
-            advance = advance + glyph.advance_();
+        for (_i, glyph) in glyphs.iter_glyphs_for_char_range(slice_range) {
+            advance = advance + glyph.advance();
         }
         RunMetrics::new(advance, self.metrics.ascent, self.metrics.descent)
     }
 
-    pub fn shape_text(@mut self, text: ~str, is_whitespace: bool) -> ARC<GlyphStore> {
+    pub fn shape_text(@mut self, text: ~str, is_whitespace: bool) -> Arc<GlyphStore> {
         do profile(time::LayoutShapingCategory, self.profiler_chan.clone()) {
             let shaper = self.get_shaper();
             do self.shape_cache.find_or_create(&text) |txt| {
                 let mut glyphs = GlyphStore::new(text.char_len(), is_whitespace);
                 shaper.shape_text(*txt, &mut glyphs);
-                ARC(glyphs)
+                Arc::new(glyphs)
             }
         }
     }
 
     pub fn get_descriptor(&self) -> FontDescriptor {
-        FontDescriptor::new(copy self.style, SelectorPlatformIdentifier(self.handle.face_identifier()))
+        FontDescriptor::new(self.style.clone(), SelectorPlatformIdentifier(self.handle.face_identifier()))
     }
 
     pub fn glyph_index(&self, codepoint: char) -> Option<GlyphIndex> {
diff --git a/src/components/gfx/font_context.rs b/src/components/gfx/font_context.rs
index 60f58d9571f..a9d71cf1aa7 100644
--- a/src/components/gfx/font_context.rs
+++ b/src/components/gfx/font_context.rs
@@ -14,7 +14,6 @@ use platform::font_context::FontContextHandle;
 
 use azure::azure_hl::BackendType;
 use std::hashmap::HashMap;
-use std::result;
 
 // TODO(Rust #3934): creating lots of new dummy styles is a workaround
 // for not being able to store symbolic enums in top-level constants.
@@ -34,7 +33,6 @@ pub trait FontContextHandleMethods {
     fn create_font_from_identifier(&self, ~str, UsedFontStyle) -> Result<FontHandle, ()>;
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 pub struct FontContext {
     instance_cache: LRUCache<FontDescriptor, @mut Font>,
     font_list: Option<FontList>, // only needed by layout
@@ -45,7 +43,6 @@ pub struct FontContext {
     profiler_chan: ProfilerChan,
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 impl<'self> FontContext {
     pub fn new(backend: BackendType,
            needs_font_list: bool,
@@ -75,7 +72,7 @@ impl<'self> FontContext {
         }
     }
 
-    priv fn get_font_list(&'self self) -> &'self FontList {
+    fn get_font_list(&'self self) -> &'self FontList {
         self.font_list.get_ref()
     }
 
@@ -113,23 +110,23 @@ impl<'self> FontContext {
         }
     }
 
-    priv fn transform_family(&self, family: &str) -> ~str {
+    fn transform_family(&self, family: &str) -> ~str {
         // FIXME: Need a find_like() in HashMap.
         let family = family.to_str();
         debug!("(transform family) searching for `%s`", family);
         match self.generic_fonts.find(&family) {
             None => family,
-            Some(mapped_family) => copy *mapped_family
+            Some(mapped_family) => (*mapped_family).clone()
         }
     }
 
-    priv fn create_font_group(&mut self, style: &SpecifiedFontStyle) -> @FontGroup {
+    fn create_font_group(&mut self, style: &SpecifiedFontStyle) -> @FontGroup {
         let mut fonts = ~[];
 
         debug!("(create font group) --- starting ---");
 
         // TODO(Issue #193): make iteration over 'font-family' more robust.
-        for style.families.split_iter(',').advance |family| {
+        for family in style.families.split_iter(',') {
             let family_name = family.trim();
             let transformed_family_name = self.transform_family(family_name);
             debug!("(create font group) transformed family is `%s`", transformed_family_name);
@@ -139,16 +136,16 @@ impl<'self> FontContext {
             };
 
             let mut found = false;
-            for result.iter().advance |font_entry| {
+            for font_entry in result.iter() {
                 found = true;
 
                 let font_id =
                   SelectorPlatformIdentifier(font_entry.handle.face_identifier());
-                let font_desc = FontDescriptor::new(copy *style, font_id);
+                let font_desc = FontDescriptor::new((*style).clone(), font_id);
 
                 let instance = self.get_font_by_descriptor(&font_desc);
 
-                do result::iter(&instance) |font: &@mut Font| { fonts.push(*font); }
+                for font in instance.iter() { fonts.push(*font); }
             };
 
             if !found {
@@ -158,19 +155,19 @@ impl<'self> FontContext {
 
         let last_resort = FontList::get_last_resort_font_families();
 
-        for last_resort.iter().advance |family| {
+        for family in last_resort.iter() {
             let result = do self.font_list.chain_ref |fl| {
                 fl.find_font_in_family(*family, style)
             };
 
-            for result.iter().advance |font_entry| {
+            for font_entry in result.iter() {
                 let font_id =
                   SelectorPlatformIdentifier(font_entry.handle.face_identifier());
-                let font_desc = FontDescriptor::new(copy *style, font_id);
+                let font_desc = FontDescriptor::new((*style).clone(), font_id);
 
                 let instance = self.get_font_by_descriptor(&font_desc);
 
-                do result::iter(&instance) |font: &@mut Font| {
+                for font in instance.iter() {
                     fonts.push(*font);
                 }
             }
@@ -178,26 +175,26 @@ impl<'self> FontContext {
 
         assert!(fonts.len() > 0);
         // TODO(Issue #179): Split FontStyle into specified and used styles
-        let used_style = copy *style;
+        let used_style = (*style).clone();
 
         debug!("(create font group) --- finished ---");
 
         @FontGroup::new(style.families.to_managed(), &used_style, fonts)
     }
 
-    priv fn create_font_instance(&self, desc: &FontDescriptor) -> Result<@mut Font, ()> {
+    fn create_font_instance(&self, desc: &FontDescriptor) -> Result<@mut Font, ()> {
         return match &desc.selector {
             // TODO(Issue #174): implement by-platform-name font selectors.
             &SelectorPlatformIdentifier(ref identifier) => { 
-                let result_handle = self.handle.create_font_from_identifier(copy *identifier,
-                                                                            copy desc.style);
-                result::chain(result_handle, |handle| {
+                let result_handle = self.handle.create_font_from_identifier((*identifier).clone(),
+                                                                            desc.style.clone());
+                do result_handle.chain |handle| {
                     Ok(Font::new_from_adopted_handle(self,
                                                      handle,
                                                      &desc.style,
                                                      self.backend,
                                                      self.profiler_chan.clone()))
-                })
+                }
             }
         };
     }
diff --git a/src/components/gfx/font_list.rs b/src/components/gfx/font_list.rs
index 835a6916eac..f3d46bb7cce 100644
--- a/src/components/gfx/font_list.rs
+++ b/src/components/gfx/font_list.rs
@@ -42,7 +42,7 @@ impl FontList {
         list
     }
 
-    priv fn refresh(&mut self, _: &FontContextHandle) {
+    fn refresh(&mut self, _: &FontContextHandle) {
         // TODO(Issue #186): don't refresh unless something actually
         // changed.  Does OSX have a notification for this event?
         //
@@ -61,7 +61,7 @@ impl FontList {
 
         // if such family exists, try to match style to a font
         let mut result: Option<@FontEntry> = None;
-        for family.iter().advance |fam| {
+        for fam in family.iter() {
             result = fam.find_font_for_style(&self.handle, style);
         }
 
@@ -76,7 +76,7 @@ impl FontList {
         result
     }
 
-    priv fn find_family(&self, family_name: &str) -> Option<@mut FontFamily> {
+    fn find_family(&self, family_name: &str) -> Option<@mut FontFamily> {
         // look up canonical name
         let family = self.family_map.find_equiv(&family_name);
 
@@ -125,8 +125,7 @@ impl FontFamily {
 
         // TODO(Issue #190): if not in the fast path above, do
         // expensive matching of weights, etc.
-        let this: &mut FontFamily = self; // FIXME: borrow checker workaround
-        for this.entries.iter().advance |entry| {
+        for entry in self.entries.iter() {
             if (style.weight.is_bold() == entry.is_bold()) && 
                (style.italic == entry.is_italic()) {
 
diff --git a/src/components/gfx/gfx.rc b/src/components/gfx/gfx.rc
index c9b7d2a2e4c..4b86374cd9a 100644
--- a/src/components/gfx/gfx.rc
+++ b/src/components/gfx/gfx.rc
@@ -10,7 +10,6 @@
 
 extern mod azure;
 extern mod geom;
-extern mod http_client;
 extern mod stb_image;
 extern mod extra;
 extern mod servo_net (name = "net");
@@ -36,7 +35,7 @@ pub use gfx_font_list = font_list;
 pub use servo_gfx_font = font;
 pub use servo_gfx_font_list = font_list;
 
-priv mod render_context;
+mod render_context;
 
 // Rendering
 pub mod color;
diff --git a/src/components/gfx/opts.rs b/src/components/gfx/opts.rs
index e1b46027cc1..8e201c7a2a7 100644
--- a/src/components/gfx/opts.rs
+++ b/src/components/gfx/opts.rs
@@ -23,7 +23,6 @@ pub struct Opts {
     output_file: Option<~str>,
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 pub fn from_cmdline_args(args: &[~str]) -> Opts {
     use extra::getopts;
 
@@ -40,13 +39,13 @@ pub fn from_cmdline_args(args: &[~str]) -> Opts {
 
     let opt_match = match getopts::getopts(args, opts) {
       result::Ok(m) => m,
-      result::Err(f) => fail!(getopts::fail_str(copy f)),
+      result::Err(f) => fail!(getopts::fail_str(f.clone())),
     };
 
     let urls = if opt_match.free.is_empty() {
         fail!(~"servo asks that you provide 1 or more URLs")
     } else {
-        copy opt_match.free
+        opt_match.free.clone()
     };
 
     let render_backend = match getopts::opt_maybe_str(&opt_match, "r") {
@@ -69,18 +68,18 @@ pub fn from_cmdline_args(args: &[~str]) -> Opts {
     };
 
     let tile_size: uint = match getopts::opt_maybe_str(&opt_match, "s") {
-        Some(tile_size_str) => uint::from_str(tile_size_str).get(),
+        Some(tile_size_str) => uint::from_str(tile_size_str).unwrap(),
         None => 512,
     };
 
     let n_render_threads: uint = match getopts::opt_maybe_str(&opt_match, "t") {
-        Some(n_render_threads_str) => uint::from_str(n_render_threads_str).get(),
+        Some(n_render_threads_str) => uint::from_str(n_render_threads_str).unwrap(),
         None => 1,      // FIXME: Number of cores.
     };
 
     // if only flag is present, default to 5 second period
     let profiler_period = do getopts::opt_default(&opt_match, "p", "5").map |period| {
-        float::from_str(*period).get()
+        float::from_str(*period).unwrap()
     };
 
     let exit_after_load = getopts::opt_present(&opt_match, "x");
diff --git a/src/components/gfx/platform/linux/font.rs b/src/components/gfx/platform/linux/font.rs
index dc2eb8bdd3b..aff744cae2d 100644
--- a/src/components/gfx/platform/linux/font.rs
+++ b/src/components/gfx/platform/linux/font.rs
@@ -73,7 +73,7 @@ impl Drop for FontHandle {
 }
 
 impl FontHandleMethods for FontHandle {
-    pub fn new_from_buffer(fctx: &FontContextHandle,
+    fn new_from_buffer(fctx: &FontContextHandle,
                            buf: ~[u8],
                            style: &SpecifiedFontStyle)
                         -> Result<FontHandle, ()> {
@@ -173,12 +173,12 @@ impl FontHandleMethods for FontHandle {
                 FontHandleMethods::new_from_buffer(fctx, buf.clone(), style)
             }
             FontSourceFile(ref file) => {
-                FontHandle::new_from_file(fctx, copy *file, style)
+                FontHandle::new_from_file(fctx, (*file).clone(), style)
             }
         }
     }
 
-    pub fn glyph_index(&self,
+    fn glyph_index(&self,
                        codepoint: char) -> Option<GlyphIndex> {
         assert!(self.face.is_not_null());
         unsafe {
@@ -192,7 +192,7 @@ impl FontHandleMethods for FontHandle {
         }
     }
 
-    pub fn glyph_h_advance(&self,
+    fn glyph_h_advance(&self,
                            glyph: GlyphIndex) -> Option<FractionalPixel> {
         assert!(self.face.is_not_null());
         unsafe {
@@ -213,7 +213,7 @@ impl FontHandleMethods for FontHandle {
         }
     }
 
-    pub fn get_metrics(&self) -> FontMetrics {
+    fn get_metrics(&self) -> FontMetrics {
         /* TODO(Issue #76): complete me */
         let face = self.get_face_rec();
 
@@ -242,7 +242,7 @@ impl FontHandleMethods for FontHandle {
 }
 
 impl<'self> FontHandle {
-    priv fn set_char_size(face: FT_Face, pt_size: float) -> Result<(), ()>{
+    fn set_char_size(face: FT_Face, pt_size: float) -> Result<(), ()>{
         let char_width = float_to_fixed_ft(pt_size) as FT_F26Dot6;
         let char_height = float_to_fixed_ft(pt_size) as FT_F26Dot6;
         let h_dpi = 72;
@@ -262,7 +262,7 @@ impl<'self> FontHandle {
 
             let mut face: FT_Face = ptr::null();
             let face_index = 0 as FT_Long;
-            do str::as_c_str(file) |file_str| {
+            do file.to_c_str().with_ref |file_str| {
                 FT_New_Face(ft_ctx, file_str,
                             face_index, ptr::to_mut_unsafe_ptr(&mut face));
             }
@@ -289,7 +289,7 @@ impl<'self> FontHandle {
 
             let mut face: FT_Face = ptr::null();
             let face_index = 0 as FT_Long;
-            do str::as_c_str(file) |file_str| {
+            do file.to_c_str().with_ref |file_str| {
                 FT_New_Face(ft_ctx, file_str,
                             face_index, ptr::to_mut_unsafe_ptr(&mut face));
             }
@@ -305,13 +305,13 @@ impl<'self> FontHandle {
         }
     }
 
-    priv fn get_face_rec(&'self self) -> &'self FT_FaceRec {
+    fn get_face_rec(&'self self) -> &'self FT_FaceRec {
         unsafe {
             &(*self.face)
         }
     }
 
-    priv fn font_units_to_au(&self, value: float) -> Au {
+    fn font_units_to_au(&self, value: float) -> Au {
         let face = self.get_face_rec();
 
         // face.size is a *c_void in the bindings, presumably to avoid
diff --git a/src/components/gfx/platform/linux/font_list.rs b/src/components/gfx/platform/linux/font_list.rs
index ae53929855c..5af148d0626 100644
--- a/src/components/gfx/platform/linux/font_list.rs
+++ b/src/components/gfx/platform/linux/font_list.rs
@@ -26,10 +26,9 @@ use platform::font_context::FontContextHandle;
 
 use std::hashmap::HashMap;
 use std::libc;
-use std::libc::c_int;
+use std::libc::{c_int, c_char};
 use std::ptr;
 use std::str;
-use std::uint;
 
 pub struct FontListHandle {
     fctx: FontContextHandle,
@@ -45,13 +44,13 @@ impl FontListHandle {
         unsafe {
             let config = FcConfigGetCurrent();
             let fontSet = FcConfigGetFonts(config, FcSetSystem);
-            for uint::range(0, (*fontSet).nfont as uint) |i| {
+            for i in range(0, (*fontSet).nfont as int) {
                 let font = (*fontSet).fonts.offset(i);
                 let family: *FcChar8 = ptr::null();
                 let mut v: c_int = 0;
-                do str::as_c_str("family") |FC_FAMILY| {
+                do "family".to_c_str().with_ref |FC_FAMILY| {
                     while FcPatternGetString(*font, FC_FAMILY, v, &family) == FcResultMatch {
-                        let family_name = str::raw::from_buf(family as *u8);
+                        let family_name = str::raw::from_c_str(family as *c_char);
                         debug!("Creating new FontFamily for family: %s", family_name);
                         let new_family = @mut FontFamily::new(family_name);
                         family_map.insert(family_name, new_family);
@@ -71,8 +70,8 @@ impl FontListHandle {
             let font_set_array_ptr = ptr::to_unsafe_ptr(&font_set);
             let pattern = FcPatternCreate();
             assert!(pattern.is_not_null());
-            do str::as_c_str("family") |FC_FAMILY| {
-                do str::as_c_str(family.family_name) |family_name| {
+            do "family".to_c_str().with_ref |FC_FAMILY| {
+                do family.family_name.to_c_str().with_ref |family_name| {
                     let ok = FcPatternAddString(pattern, FC_FAMILY, family_name as *FcChar8);
                     assert!(ok != 0);
                 }
@@ -81,10 +80,10 @@ impl FontListHandle {
             let object_set = FcObjectSetCreate();
             assert!(object_set.is_not_null());
 
-            do str::as_c_str("file") |FC_FILE| {
+            do "file".to_c_str().with_ref |FC_FILE| {
                 FcObjectSetAdd(object_set, FC_FILE);
             }
-            do str::as_c_str("index") |FC_INDEX| {
+            do "index".to_c_str().with_ref |FC_INDEX| {
                 FcObjectSetAdd(object_set, FC_INDEX);
             }
 
@@ -92,9 +91,9 @@ impl FontListHandle {
 
             debug!("found %? variations", (*matches).nfont);
 
-            for uint::range(0, (*matches).nfont as uint) |i| {
+            for i in range(0, (*matches).nfont as int) {
                 let font = (*matches).fonts.offset(i);
-                let file = do str::as_c_str("file") |FC_FILE| {
+                let file = do "file".to_c_str().with_ref |FC_FILE| {
                     let file: *FcChar8 = ptr::null();
                     if FcPatternGetString(*font, FC_FILE, 0, &file) == FcResultMatch {
                         str::raw::from_c_str(file as *libc::c_char)
@@ -102,7 +101,7 @@ impl FontListHandle {
                         fail!();
                     }
                 };
-                let index = do str::as_c_str("index") |FC_INDEX| {
+                let index = do "index".to_c_str().with_ref |FC_INDEX| {
                     let index: libc::c_int = 0;
                     if FcPatternGetInteger(*font, FC_INDEX, 0, &index) == FcResultMatch {
                         index
@@ -151,8 +150,8 @@ pub fn path_from_identifier(name: ~str, style: &UsedFontStyle) -> Result<~str, (
         let config = FcConfigGetCurrent();
         let wrapper = AutoPattern { pattern: FcPatternCreate() };
         let pattern = wrapper.pattern;
-        let res = do str::as_c_str("family") |FC_FAMILY| {
-            do str::as_c_str(name) |family| {
+        let res = do "family".to_c_str().with_ref |FC_FAMILY| {
+            do name.to_c_str().with_ref |family| {
                 FcPatternAddString(pattern, FC_FAMILY, family as *FcChar8)
             }
         };
@@ -162,7 +161,7 @@ pub fn path_from_identifier(name: ~str, style: &UsedFontStyle) -> Result<~str, (
         }
 
         if style.italic {
-            let res = do str::as_c_str("slant") |FC_SLANT| {
+            let res = do "slant".to_c_str().with_ref |FC_SLANT| {
                 FcPatternAddInteger(pattern, FC_SLANT, FC_SLANT_ITALIC)
             };
             if res != 1 {
@@ -171,7 +170,7 @@ pub fn path_from_identifier(name: ~str, style: &UsedFontStyle) -> Result<~str, (
             }
         }
         if style.weight.is_bold() {
-            let res = do str::as_c_str("weight") |FC_WEIGHT| {
+            let res = do "weight".to_c_str().with_ref |FC_WEIGHT| {
                 FcPatternAddInteger(pattern, FC_WEIGHT, FC_WEIGHT_BOLD)
             };
             if res != 1 {
@@ -194,13 +193,13 @@ pub fn path_from_identifier(name: ~str, style: &UsedFontStyle) -> Result<~str, (
         }
 
         let file: *FcChar8 = ptr::null();
-        let res = do str::as_c_str("file") |FC_FILE| {
+        let res = do "file".to_c_str().with_ref |FC_FILE| {
             FcPatternGetString(result_pattern, FC_FILE, 0, &file)
         };
         if res != FcResultMatch {
             debug!("getting filename for font failed");
             return Err(());
         }
-        Ok(str::raw::from_buf(file as *u8))
+        Ok(str::raw::from_c_str(file as *c_char))
     }
 }
diff --git a/src/components/gfx/platform/macos/font_context.rs b/src/components/gfx/platform/macos/font_context.rs
index a96390d3537..79ebf1548c3 100644
--- a/src/components/gfx/platform/macos/font_context.rs
+++ b/src/components/gfx/platform/macos/font_context.rs
@@ -8,8 +8,6 @@ use platform::macos::font::FontHandle;
 
 use core_text;
 
-use std::result;
-
 pub struct FontContextHandle {
     ctx: ()
 }
@@ -33,7 +31,7 @@ impl FontContextHandleMethods for FontContextHandle {
                                    style: UsedFontStyle)
                                 -> Result<FontHandle, ()> {
         let ctfont_result = core_text::font::new_from_name(name, style.pt_size);
-        do result::chain(ctfont_result) |ctfont| {
+        do ctfont_result.chain |ctfont| {
             FontHandle::new_from_CTFont(self, ctfont)
         }
     }
diff --git a/src/components/gfx/platform/macos/font_list.rs b/src/components/gfx/platform/macos/font_list.rs
index 85e22405745..22016f18fe4 100644
--- a/src/components/gfx/platform/macos/font_list.rs
+++ b/src/components/gfx/platform/macos/font_list.rs
@@ -12,11 +12,9 @@ use core_foundation::array::CFArray;
 use core_foundation::base::CFWrapper;
 use core_foundation::string::{CFString, CFStringRef};
 use core_text::font_collection::CTFontCollectionMethods;
-use core_text::font_descriptor::CTFontDescriptorRef;
 use core_text;
 
 use std::hashmap::HashMap;
-use std::result;
 
 pub struct FontListHandle {
     fctx: FontContextHandle,
@@ -32,24 +30,25 @@ impl FontListHandle {
     pub fn get_available_families(&self) -> FontFamilyMap {
         let family_names: CFArray<CFStringRef> = core_text::font_collection::get_family_names();
         let mut family_map: FontFamilyMap = HashMap::new();
-        for family_names.each |&strref: &CFStringRef| {
+        for strref in family_names.iter() {
             let family_name = CFString::wrap_shared(strref).to_str();
             debug!("Creating new FontFamily for family: %s", family_name);
 
             let new_family = @mut FontFamily::new(family_name);
             family_map.insert(family_name, new_family);
         }
-        return family_map;
+        family_map
     }
 
     pub fn load_variations_for_family(&self, family: @mut FontFamily) {
         debug!("Looking for faces of family: %s", family.family_name);
 
         let family_collection = core_text::font_collection::create_for_family(family.family_name);
-        for family_collection.get_descriptors().each |descref: &CTFontDescriptorRef| {
-            let desc = CFWrapper::wrap_shared(*descref);
+        let family_descriptors = family_collection.get_descriptors();
+        for descref in family_descriptors.iter() {
+            let desc = CFWrapper::wrap_shared(descref);
             let font = core_text::font::new_from_descriptor(&desc, 0.0);
-            let handle = result::unwrap(FontHandle::new_from_CTFont(&self.fctx, font));
+            let handle = FontHandle::new_from_CTFont(&self.fctx, font).unwrap();
 
             debug!("Creating new FontEntry for face: %s", handle.face_name());
             let entry = @FontEntry::new(handle);
diff --git a/src/components/gfx/render_context.rs b/src/components/gfx/render_context.rs
index 89567f1fa3b..d7e2242935e 100644
--- a/src/components/gfx/render_context.rs
+++ b/src/components/gfx/render_context.rs
@@ -16,7 +16,7 @@ use geom::rect::Rect;
 use geom::size::Size2D;
 use geom::side_offsets::SideOffsets2D;
 use servo_net::image::base::Image;
-use extra::arc::ARC;
+use extra::arc::Arc;
 
 pub struct RenderContext<'self> {
     canvas: &'self LayerBuffer,
@@ -77,7 +77,7 @@ impl<'self> RenderContext<'self>  {
         self.canvas.draw_target.stroke_line(start, end, &pattern, &stroke_opts, &draw_opts);
     }
 
-    pub fn draw_image(&self, bounds: Rect<Au>, image: ARC<~Image>) {
+    pub fn draw_image(&self, bounds: Rect<Au>, image: Arc<~Image>) {
         let image = image.get();
         let size = Size2D(image.width as i32, image.height as i32);
         let stride = image.width * 4;
diff --git a/src/components/gfx/render_task.rs b/src/components/gfx/render_task.rs
index dab31cdc2f4..6ddbb19df64 100644
--- a/src/components/gfx/render_task.rs
+++ b/src/components/gfx/render_task.rs
@@ -39,6 +39,7 @@ pub enum Msg {
 }
 
 /// A request from the compositor to the renderer for tiles that need to be (re)displayed.
+#[deriving(Clone)]
 pub struct BufferRequest {
     // The rect in pixels that will be drawn to the screen
     screen_rect: Rect<uint>,
@@ -70,7 +71,7 @@ impl RenderChan {
     }
 }
 
-priv struct RenderTask<C> {
+struct RenderTask<C> {
     id: PipelineId,
     port: Port<Msg>,
     compositor: C,
@@ -87,7 +88,7 @@ priv struct RenderTask<C> {
     /// Permission to send paint messages to the compositor
     paint_permission: bool,
     /// Cached copy of last layers rendered
-    last_paint_msg: Option<(arc::ARC<LayerBufferSet>, Size2D<uint>)>,
+    last_paint_msg: Option<(arc::Arc<LayerBufferSet>, Size2D<uint>)>,
 }
 
 impl<C: RenderListener + Send> RenderTask<C> {
@@ -112,7 +113,7 @@ impl<C: RenderListener + Send> RenderTask<C> {
                 id: id,
                 port: port.take(),
                 compositor: compositor,
-                font_ctx: @mut FontContext::new(copy opts.render_backend,
+                font_ctx: @mut FontContext::new(opts.render_backend.clone(),
                                                 false,
                                                 profiler_chan.clone()),
                 opts: opts,
@@ -179,7 +180,7 @@ impl<C: RenderListener + Send> RenderTask<C> {
 
             // Divide up the layer into tiles.
             do time::profile(time::RenderingPrepBuffCategory, self.profiler_chan.clone()) {
-                for tiles.iter().advance |tile| {
+                for tile in tiles.iter() {
                     let width = tile.screen_rect.size.width;
                     let height = tile.screen_rect.size.height;
                     
@@ -230,7 +231,7 @@ impl<C: RenderListener + Send> RenderTask<C> {
             let layer_buffer_set = LayerBufferSet {
                 buffers: new_buffers,
             };
-            let layer_buffer_set = arc::ARC(layer_buffer_set);
+            let layer_buffer_set = arc::Arc::new(layer_buffer_set);
 
             debug!("render_task: returning surface");
             if self.paint_permission {
diff --git a/src/components/gfx/surface.rs b/src/components/gfx/surface.rs
index 4c965db812b..b30c165c08b 100644
--- a/src/components/gfx/surface.rs
+++ b/src/components/gfx/surface.rs
@@ -28,7 +28,7 @@ pub struct ImageSurface {
 impl ImageSurface {
     pub fn new(size: Size2D<int>, format: format) -> ImageSurface {
         ImageSurface {
-            size: copy size,
+            size: size.clone(),
             format: format,
             buffer: vec::from_elem((size.area() as uint) * format.bpp(), 0u8)
         }
diff --git a/src/components/gfx/text/glyph.rs b/src/components/gfx/text/glyph.rs
index f6569cc959b..d5e7bcd8ebb 100644
--- a/src/components/gfx/text/glyph.rs
+++ b/src/components/gfx/text/glyph.rs
@@ -12,8 +12,8 @@ use std::cmp::{Ord, Eq};
 use std::num::NumCast;
 use std::u16;
 use std::vec;
-use std::uint;
 use std::util;
+use std::iterator;
 use geom::point::Point2D;
 use extra::sort;
 
@@ -25,6 +25,7 @@ use extra::sort;
 /// In the uncommon case (multiple glyphs per unicode character, large glyph index/advance, or
 /// glyph offsets), we pack the glyph count into GlyphEntry, and store the other glyph information
 /// in DetailedGlyphStore.
+#[deriving(Clone)]
 struct GlyphEntry {
     value: u32
 }
@@ -256,6 +257,7 @@ impl GlyphEntry {
 
 // Stores data for a detailed glyph, in the case that several glyphs
 // correspond to one character, or the glyph's data couldn't be packed.
+#[deriving(Clone)]
 struct DetailedGlyph {
     index: GlyphIndex,
     // glyph's advance, in the text's direction (RTL or RTL)
@@ -274,7 +276,7 @@ impl DetailedGlyph {
     }
 }
 
-#[deriving(Eq)]
+#[deriving(Eq, Clone)]
 struct DetailedGlyphRecord {
     // source string offset/GlyphEntry offset in the TextRun
     entry_offset: uint,
@@ -459,7 +461,7 @@ enum GlyphInfo<'self> {
 }
 
 impl<'self> GlyphInfo<'self> {
-    fn index(self) -> GlyphIndex {
+    pub fn index(self) -> GlyphIndex {
         match self {
             SimpleGlyphInfo(store, entry_i) => store.entry_buffer[entry_i].index(),
             DetailGlyphInfo(store, entry_i, detail_j) => {
@@ -470,7 +472,7 @@ impl<'self> GlyphInfo<'self> {
 
     #[inline(always)]
     // FIXME: Resolution conflicts with IteratorUtil trait so adding trailing _
-    fn advance_(self) -> Au {
+    pub fn advance(self) -> Au {
         match self {
             SimpleGlyphInfo(store, entry_i) => store.entry_buffer[entry_i].advance(),
             DetailGlyphInfo(store, entry_i, detail_j) => {
@@ -479,7 +481,7 @@ impl<'self> GlyphInfo<'self> {
         }
     }
 
-    fn offset(self) -> Option<Point2D<Au>> {
+    pub fn offset(self) -> Option<Point2D<Au>> {
         match self {
             SimpleGlyphInfo(_, _) => None,
             DetailGlyphInfo(store, entry_i, detail_j) => {
@@ -488,14 +490,14 @@ impl<'self> GlyphInfo<'self> {
         }
     }
 
-    fn is_ligature_start(self) -> bool {
+    pub fn is_ligature_start(self) -> bool {
         match self {
             SimpleGlyphInfo(store, entry_i) => store.entry_buffer[entry_i].is_ligature_start(),
             DetailGlyphInfo(store, entry_i, _) => store.entry_buffer[entry_i].is_ligature_start()
         }
     }
 
-    fn is_cluster_start(self) -> bool {
+    pub fn is_cluster_start(self) -> bool {
         match self {
             SimpleGlyphInfo(store, entry_i) => store.entry_buffer[entry_i].is_cluster_start(),
             DetailGlyphInfo(store, entry_i, _) => store.entry_buffer[entry_i].is_cluster_start()
@@ -597,62 +599,24 @@ impl<'self> GlyphStore {
         self.entry_buffer[i] = entry;
     }
 
-    pub fn iter_glyphs_for_char_index(&'self self,
-                                  i: uint,
-                                  cb: &fn(uint, &GlyphInfo<'self>) -> bool)
-                                  -> bool {
-        assert!(i < self.entry_buffer.len());
-
-        let entry = &self.entry_buffer[i];
-        match entry.is_simple() {
-            true => { 
-                let proxy = &SimpleGlyphInfo(self, i);
-                cb(i, proxy);
-            },
-            false => {
-                let glyphs = self.detail_store.get_detailed_glyphs_for_entry(i,
-                                                                             entry.glyph_count());
-                for uint::range(0, glyphs.len()) |j| {
-                    let proxy = &DetailGlyphInfo(self, i, j as u16);
-                    cb(i, proxy);
-                }
-            }
-        }
-        true
+    pub fn iter_glyphs_for_char_index(&'self self, i: uint) -> GlyphIterator<'self> {
+        self.iter_glyphs_for_char_range(&Range::new(i, 1))
     }
 
-    pub fn iter_glyphs_for_char_range(&'self self,
-                                  range: &Range,
-                                  callback: &fn(uint, &GlyphInfo<'self>) -> bool)
-                                  -> bool {
-        if range.begin() >= self.entry_buffer.len() {
-            error!("iter_glyphs_for_range: range.begin beyond length!");
-            return false
+    pub fn iter_glyphs_for_char_range(&'self self, rang: &Range) -> GlyphIterator<'self> {
+        if rang.begin() >= self.entry_buffer.len() {
+            fail!("iter_glyphs_for_range: range.begin beyond length!");
         }
-        if range.end() > self.entry_buffer.len() {
-            error!("iter_glyphs_for_range: range.end beyond length!");
-            return false
+        if rang.end() > self.entry_buffer.len() {
+            fail!("iter_glyphs_for_range: range.end beyond length!");
         }
 
-        for range.eachi |i| {
-            // FIXME: Work around rust#2202. We should be able to pass the callback directly.
-            if !self.iter_glyphs_for_char_index(i, |a, b| callback(a, b)) {
-                break
-            }
+        GlyphIterator {
+            store:       self,
+            char_index:  rang.begin(),
+            char_range:  rang.eachi(),
+            glyph_range: None
         }
-
-        true
-    }
-
-    pub fn iter_all_glyphs(&'self self, callback: &fn(uint, &GlyphInfo<'self>) -> bool) -> bool {
-        for uint::range(0, self.entry_buffer.len()) |i| {
-            // FIXME: Work around rust#2202. We should be able to pass the callback directly.
-            if !self.iter_glyphs_for_char_index(i, |a, b| callback(a, b)) {
-                break;
-            }
-        }
-
-        true
     }
 
     // getter methods
@@ -711,3 +675,49 @@ impl<'self> GlyphStore {
         self.entry_buffer[i] = entry.set_can_break_before(t);
     }
 }
+
+pub struct GlyphIterator<'self> {
+    priv store:       &'self GlyphStore,
+    priv char_index:  uint,
+    priv char_range:  iterator::Range<uint>,
+    priv glyph_range: Option<iterator::Range<uint>>,
+}
+
+impl<'self> Iterator<(uint, GlyphInfo<'self>)> for GlyphIterator<'self> {
+    // I tried to start with something simpler and apply FlatMap, but the
+    // inability to store free variables in the FlatMap struct was problematic.
+
+    fn next(&mut self) -> Option<(uint, GlyphInfo<'self>)> {
+        // Would use 'match' here but it borrows contents in a way that
+        // interferes with mutation.
+        if self.glyph_range.is_some() {
+            match self.glyph_range.unwrap().next() {
+                Some(j) => Some((self.char_index,
+                    DetailGlyphInfo(self.store, self.char_index, j as u16))),
+                None => {
+                    // No more glyphs for current character.  Try to get another.
+                    self.glyph_range = None;
+                    self.next()
+                }
+            }
+        } else {
+            // No glyph range.  Look at next character.
+            match self.char_range.next() {
+                Some(i) => {
+                    self.char_index = i;
+                    assert!(i < self.store.entry_buffer.len());
+                    let entry = &self.store.entry_buffer[i];
+                    if entry.is_simple() {
+                        Some((self.char_index, SimpleGlyphInfo(self.store, i)))
+                    } else {
+                        let glyphs = self.store.detail_store
+                                     .get_detailed_glyphs_for_entry(i, entry.glyph_count());
+                        self.glyph_range = Some(range(0, glyphs.len()));
+                        self.next()
+                    }
+                },
+                None => None
+            }
+        }
+    }
+}
diff --git a/src/components/gfx/text/shaping/harfbuzz.rs b/src/components/gfx/text/shaping/harfbuzz.rs
index 851beb87c8c..75358329e1e 100644
--- a/src/components/gfx/text/shaping/harfbuzz.rs
+++ b/src/components/gfx/text/shaping/harfbuzz.rs
@@ -16,7 +16,6 @@ use std::cast::transmute;
 use std::libc::{c_uint, c_int, c_void, c_char};
 use std::ptr;
 use std::ptr::null;
-use std::str;
 use std::uint;
 use std::util::ignore;
 use std::vec;
@@ -86,7 +85,7 @@ impl ShapedGlyphData {
     fn byte_offset_of_glyph(&self, i: uint) -> uint {
         assert!(i < self.count);
 
-        let glyph_info_i = ptr::offset(self.glyph_infos, i);
+        let glyph_info_i = ptr::offset(self.glyph_infos, i as int);
         unsafe {
             (*glyph_info_i).cluster as uint
         }
@@ -101,8 +100,8 @@ impl ShapedGlyphData {
         assert!(i < self.count);
 
         unsafe {
-            let glyph_info_i = ptr::offset(self.glyph_infos, i);
-            let pos_info_i = ptr::offset(self.pos_infos, i);
+            let glyph_info_i = ptr::offset(self.glyph_infos, i as int);
+            let pos_info_i = ptr::offset(self.pos_infos, i as int);
             let x_offset = Shaper::fixed_to_float((*pos_info_i).x_offset);
             let y_offset = Shaper::fixed_to_float((*pos_info_i).y_offset);
             let x_advance = Shaper::fixed_to_float((*pos_info_i).x_advance);
@@ -216,8 +215,8 @@ impl ShaperMethods for Shaper {
             let hb_buffer: *hb_buffer_t = hb_buffer_create();
             hb_buffer_set_direction(hb_buffer, HB_DIRECTION_LTR);
 
-            // Using as_buf because it never does a copy - we don't need the trailing null
-            do str::as_buf(text) |ctext: *u8, _: uint| {
+            // Using as_imm_buf because it never does a copy - we don't need the trailing null
+            do text.as_imm_buf |ctext: *u8, _: uint| {
                 hb_buffer_add_utf8(hb_buffer,
                                    ctext as *c_char,
                                    text.len() as c_int,
@@ -272,7 +271,7 @@ impl Shaper {
         }
 
         debug!("(glyph idx) -> (text byte offset)");
-        for uint::range(0, glyph_data.len()) |i| {
+        for i in range(0, glyph_data.len()) {
             // loc refers to a *byte* offset within the utf8 string.
             let loc = glyph_data.byte_offset_of_glyph(i);
             if loc < byte_max {
@@ -335,7 +334,7 @@ impl Shaper {
                 // extend glyph range to max glyph index covered by char_span,
                 // in cases where one char made several glyphs and left some unassociated chars.
                 let mut max_glyph_idx = glyph_span.end();
-                for char_byte_span.eachi |i| {
+                for i in char_byte_span.eachi() {
                     if byteToGlyph[i] > NO_GLYPH {
                         max_glyph_idx = uint::max(byteToGlyph[i] as uint, max_glyph_idx);
                     }
@@ -359,7 +358,7 @@ impl Shaper {
                         probably doesn't work.");
 
                 let mut all_glyphs_are_within_cluster: bool = true;
-                for glyph_span.eachi |j| {
+                for j in glyph_span.eachi() {
                     let loc = glyph_data.byte_offset_of_glyph(j);
                     if !char_byte_span.contains(loc) {
                         all_glyphs_are_within_cluster = false;
@@ -398,7 +397,7 @@ impl Shaper {
             // cspan:  [-]
             // covsp:  [---------------]
 
-            let mut covered_byte_span = copy char_byte_span;
+            let mut covered_byte_span = char_byte_span.clone();
             // extend, clipping at end of text range.
             while covered_byte_span.end() < byte_max
                     && byteToGlyph[covered_byte_span.end()] == NO_GLYPH {
@@ -438,7 +437,7 @@ impl Shaper {
                 // collect all glyphs to be assigned to the first character.
                 let mut datas = ~[];
 
-                for glyph_span.eachi |glyph_i| {
+                for glyph_i in glyph_span.eachi() {
                     let shape = glyph_data.get_entry_for_glyph(glyph_i, &mut y_pos);
                     datas.push(GlyphData::new(shape.codepoint,
                                               shape.advance,
diff --git a/src/components/gfx/text/text_run.rs b/src/components/gfx/text/text_run.rs
index c436181977c..f22b0d94d28 100644
--- a/src/components/gfx/text/text_run.rs
+++ b/src/components/gfx/text/text_run.rs
@@ -2,27 +2,29 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use std::vec::VecIterator;
+
 use font_context::FontContext;
 use geometry::Au;
 use text::glyph::GlyphStore;
 use font::{Font, FontDescriptor, RunMetrics};
 use servo_util::range::Range;
-use extra::arc::ARC;
+use extra::arc::Arc;
 
 /// A text run.
 pub struct TextRun {
     text: ~str,
     font: @mut Font,
     underline: bool,
-    glyphs: ~[ARC<GlyphStore>],
+    glyphs: ~[Arc<GlyphStore>],
 }
 
-/// This is a hack until TextRuns are normally sendable, or we instead use ARC<TextRun> everywhere.
+/// This is a hack until TextRuns are normally sendable, or we instead use Arc<TextRun> everywhere.
 pub struct SendableTextRun {
     text: ~str,
     font: FontDescriptor,
     underline: bool,
-    priv glyphs: ~[ARC<GlyphStore>],
+    priv glyphs: ~[Arc<GlyphStore>],
 }
 
 impl SendableTextRun {
@@ -33,7 +35,7 @@ impl SendableTextRun {
         };
 
         TextRun {
-            text: copy self.text,
+            text: self.text.clone(),
             font: font,
             underline: self.underline,
             glyphs: self.glyphs.clone(),
@@ -41,6 +43,78 @@ impl SendableTextRun {
     }
 }
 
+pub struct SliceIterator<'self> {
+    priv glyph_iter: VecIterator<'self, Arc<GlyphStore>>,
+    priv range:      Range,
+    priv offset:     uint,
+}
+
+impl<'self> Iterator<(&'self GlyphStore, uint, Range)> for SliceIterator<'self> {
+    fn next(&mut self) -> Option<(&'self GlyphStore, uint, Range)> {
+        loop {
+            let slice_glyphs = self.glyph_iter.next();
+            if slice_glyphs.is_none() {
+                return None;
+            }
+            let slice_glyphs = slice_glyphs.unwrap().get();
+
+            let slice_range = Range::new(self.offset, slice_glyphs.char_len());
+            let mut char_range = self.range.intersect(&slice_range);
+            char_range.shift_by(-(self.offset.to_int()));
+
+            let old_offset = self.offset;
+            self.offset += slice_glyphs.char_len();
+            if !char_range.is_empty() {
+                return Some((slice_glyphs, old_offset, char_range))
+            }
+        }
+    }
+}
+
+pub struct LineIterator<'self> {
+    priv range:  Range,
+    priv clump:  Option<Range>,
+    priv slices: SliceIterator<'self>,
+}
+
+impl<'self> Iterator<Range> for LineIterator<'self> {
+    fn next(&mut self) -> Option<Range> {
+        // Loop until we hit whitespace and are in a clump.
+        loop {
+            match self.slices.next() {
+                Some((glyphs, offset, slice_range)) => {
+                    match (glyphs.is_whitespace(), self.clump) {
+                        (false, Some(ref mut c))  => {
+                            c.extend_by(slice_range.length().to_int());
+                        }
+                        (false, None) => {
+                            let mut c = slice_range;
+                            c.shift_by(offset.to_int());
+                            self.clump = Some(c);
+                        }
+                        (true, None)    => { /* chomp whitespace */ }
+                        (true, Some(c)) => {
+                            self.clump = None;
+                            // The final whitespace clump is not included.
+                            return Some(c);
+                        }
+                    }
+                },
+                None => {
+                    // flush any remaining chars as a line
+                    if self.clump.is_some() {
+                        let mut c = self.clump.take_unwrap();
+                        c.extend_to(self.range.end());
+                        return Some(c);
+                    } else {
+                        return None;
+                    }
+                }
+            }
+        }
+    }
+}
+
 impl<'self> TextRun {
     pub fn new(font: @mut Font, text: ~str, underline: bool) -> TextRun {
         let glyphs = TextRun::break_and_shape(font, text);
@@ -58,7 +132,7 @@ impl<'self> TextRun {
         self.font.teardown();
     }
 
-    pub fn break_and_shape(font: @mut Font, text: &str) -> ~[ARC<GlyphStore>] {
+    pub fn break_and_shape(font: @mut Font, text: &str) -> ~[Arc<GlyphStore>] {
         // TODO(Issue #230): do a better job. See Gecko's LineBreaker.
 
         let mut glyphs = ~[];
@@ -115,7 +189,7 @@ impl<'self> TextRun {
 
     pub fn serialize(&self) -> SendableTextRun {
         SendableTextRun {
-            text: copy self.text,
+            text: self.text.clone(),
             font: self.font.get_descriptor(),
             underline: self.underline,
             glyphs: self.glyphs.clone(),
@@ -128,10 +202,10 @@ impl<'self> TextRun {
         }
     }
 
-    pub fn glyphs(&'self self) -> &'self ~[ARC<GlyphStore>] { &self.glyphs }
+    pub fn glyphs(&'self self) -> &'self ~[Arc<GlyphStore>] { &self.glyphs }
 
     pub fn range_is_trimmable_whitespace(&self, range: &Range) -> bool {
-        for self.iter_slices_for_range(range) |slice_glyphs, _, _| {
+        for (slice_glyphs, _, _) in self.iter_slices_for_range(range) {
             if !slice_glyphs.is_whitespace() { return false; }
         }
         true
@@ -148,61 +222,27 @@ impl<'self> TextRun {
     pub fn min_width_for_range(&self, range: &Range) -> Au {
         let mut max_piece_width = Au(0);
         debug!("iterating outer range %?", range);
-        for self.iter_slices_for_range(range) |glyphs, offset, slice_range| {
+        for (glyphs, offset, slice_range) in self.iter_slices_for_range(range) {
             debug!("iterated on %?[%?]", offset, slice_range);
-            let metrics = self.font.measure_text_for_slice(glyphs, slice_range);
+            let metrics = self.font.measure_text_for_slice(glyphs, &slice_range);
             max_piece_width = Au::max(max_piece_width, metrics.advance_width);
         }
         max_piece_width
     }
 
-    pub fn iter_slices_for_range(&self,
-                                 range: &Range,
-                                 f: &fn(&GlyphStore, uint, &Range) -> bool)
-                                 -> bool {
-        let mut offset = 0;
-        for self.glyphs.iter().advance |slice_glyphs| {
-            // Determine the range of this slice that we need.
-            let slice_range = Range::new(offset, slice_glyphs.get().char_len());
-            let mut char_range = range.intersect(&slice_range);
-            char_range.shift_by(-(offset.to_int()));
-
-            let unwrapped_glyphs = slice_glyphs.get();
-            if !char_range.is_empty() {
-                if !f(unwrapped_glyphs, offset, &char_range) { break }
-            }
-            offset += unwrapped_glyphs.char_len();
+    pub fn iter_slices_for_range(&'self self, range: &Range) -> SliceIterator<'self> {
+        SliceIterator {
+            glyph_iter: self.glyphs.iter(),
+            range:      *range,
+            offset:     0,
         }
-        true
     }
 
-    pub fn iter_natural_lines_for_range(&self, range: &Range, f: &fn(&Range) -> bool) -> bool {
-        let mut clump = Range::new(range.begin(), 0);
-        let mut in_clump = false;
-
-        for self.iter_slices_for_range(range) |glyphs, offset, slice_range| {
-            match (glyphs.is_whitespace(), in_clump) {
-                (false, true)  => { clump.extend_by(slice_range.length().to_int()); }
-                (false, false) => {
-                    in_clump = true;
-                    clump = *slice_range;
-                    clump.shift_by(offset.to_int());
-                }
-                (true, false)  => { /* chomp whitespace */ }
-                (true, true)   => {
-                    in_clump = false;
-                    // The final whitespace clump is not included.
-                    if !f(&clump) { break }
-                }
-            }
+    pub fn iter_natural_lines_for_range(&'self self, range: &Range) -> LineIterator<'self> {
+        LineIterator {
+            range:  *range,
+            clump:  None,
+            slices: self.iter_slices_for_range(range),
         }
-        
-        // flush any remaining chars as a line
-        if in_clump {
-            clump.extend_to(range.end());
-            f(&clump);
-        }
-
-        true
     }
 }
diff --git a/src/components/gfx/text/util.rs b/src/components/gfx/text/util.rs
index e808d08e339..13e8e369926 100644
--- a/src/components/gfx/text/util.rs
+++ b/src/components/gfx/text/util.rs
@@ -24,7 +24,7 @@ pub fn transform_text(text: &str, mode: CompressionMode, incoming_whitespace: bo
     let mut out_str: ~str = ~"";
     let out_whitespace = match mode {
         CompressNone | DiscardNewline => {
-            for text.iter().advance |ch: char| {
+            for ch in text.iter() {
                 if is_discardable_char(ch, mode) {
                     // TODO: record skipped char
                 } else {
@@ -40,7 +40,7 @@ pub fn transform_text(text: &str, mode: CompressionMode, incoming_whitespace: bo
 
         CompressWhitespace | CompressWhitespaceNewline => {
             let mut in_whitespace: bool = incoming_whitespace;
-            for text.iter().advance |ch: char| {
+            for ch in text.iter() {
                 // TODO: discard newlines between CJK chars
                 let mut next_in_whitespace: bool = is_in_whitespace(ch, mode);
                 
@@ -134,7 +134,7 @@ fn test_transform_compress_none() {
                                  ~"foobarbaz\n\n"];
     let mode = CompressNone;
 
-    for uint::range(0, test_strs.len()) |i| {
+    for i in range(0, test_strs.len()) {
         (trimmed_str, _out) = transform_text(test_strs[i], mode, true);
         assert!(trimmed_str == test_strs[i])
     }
@@ -162,7 +162,7 @@ fn test_transform_discard_newline() {
     assert!(test_strs.len() == oracle_strs.len());
     let mode = DiscardNewline;
 
-    for uint::range(0, test_strs.len()) |i| {
+    for i in range(0, test_strs.len()) {
         (trimmed_str, _out) = transform_text(test_strs[i], mode, true);
         assert!(trimmed_str == oracle_strs[i])
     }
@@ -189,7 +189,7 @@ fn test_transform_compress_whitespace() {
     assert!(test_strs.len() == oracle_strs.len());
     let mode = CompressWhitespace;
 
-    for uint::range(0, test_strs.len()) |i| {
+    for i in range(0, test_strs.len()) {
         (trimmed_str, _out) = transform_text(test_strs[i], mode, true);
         assert!(trimmed_str == oracle_strs[i])
     }
@@ -216,7 +216,7 @@ fn test_transform_compress_whitespace_newline() {
     assert!(test_strs.len() == oracle_strs.len());
     let mode = CompressWhitespaceNewline;
 
-    for uint::range(0, test_strs.len()) |i| {
+    for i in range(0, test_strs.len()) {
         (trimmed_str, _out) = transform_text(test_strs[i], mode, true);
         assert!(trimmed_str == oracle_strs[i])
     }
@@ -245,7 +245,7 @@ fn test_transform_compress_whitespace_newline() {
     assert!(test_strs.len() == oracle_strs.len());
     let mode = CompressWhitespaceNewline;
 
-    for uint::range(0, test_strs.len()) |i| {
+    for i in range(0, test_strs.len()) {
         (trimmed_str, _out) = transform_text(test_strs[i], mode, false);
         assert!(trimmed_str == oracle_strs[i])
     }
diff --git a/src/components/main/compositing/compositor_layer.rs b/src/components/main/compositing/compositor_layer.rs
index 083dc5312c5..c846e58a175 100644
--- a/src/components/main/compositing/compositor_layer.rs
+++ b/src/components/main/compositing/compositor_layer.rs
@@ -87,7 +87,7 @@ impl CompositorLayer {
     // true; otherwise returns false, so a parent layer can scroll instead.
     pub fn scroll(&mut self, delta: Point2D<f32>, cursor: Point2D<f32>, window_size: Size2D<f32>) -> bool {
         let cursor = cursor - self.scroll_offset;
-        for self.children.mut_iter().filter(|x| !x.child.hidden).advance |child| {
+        for child in self.children.mut_iter().filter(|x| !x.child.hidden) {
             match child.container.scissor {
                 None => {
                     error!("CompositorLayer: unable to perform cursor hit test for layer");
@@ -131,7 +131,7 @@ impl CompositorLayer {
     // page coordinates.
     pub fn send_mouse_event(&self, event: MouseWindowEvent, cursor: Point2D<f32>) {
         let cursor = cursor - self.scroll_offset;
-        for self.children.iter().filter(|&x| !x.child.hidden).advance |child| {
+        for child in self.children.iter().filter(|&x| !x.child.hidden) {
             match child.container.scissor {
                 None => {
                     error!("CompositorLayer: unable to perform cursor hit test for layer");
@@ -197,7 +197,7 @@ impl CompositorLayer {
             }
         };
         self.children.mut_iter().filter(|x| !x.child.hidden)
-            .transform(transform)
+            .map(transform)
             .fold(false, |a, b| a || b) || redisplay
     }
 
@@ -206,7 +206,7 @@ impl CompositorLayer {
     // and clip the layer to the specified size in page coordinates.
     // This method returns false if the specified layer is not found.
     pub fn set_clipping_rect(&mut self, pipeline_id: PipelineId, new_rect: Rect<f32>) -> bool {
-            for self.children.iter().advance |child_node| {
+        for child_node in self.children.iter() {
             if pipeline_id != child_node.child.pipeline.id {
                 loop;
             }
@@ -219,7 +219,7 @@ impl CompositorLayer {
         }
         
         // ID does not match any of our immediate children, so recurse on descendents (including hidden children)
-        self.children.mut_iter().transform(|x| &mut x.child).any(|x| x.set_clipping_rect(pipeline_id, new_rect))
+        self.children.mut_iter().map(|x| &mut x.child).any(|x| x.set_clipping_rect(pipeline_id, new_rect))
     }
 
 
@@ -265,15 +265,15 @@ impl CompositorLayer {
         
         // Delete old layer.
         while current_layer_child.is_some() {
-            let trash = current_layer_child.get();
-            do current_layer_child.get().with_common |common| {
+            let trash = current_layer_child.unwrap();
+            do current_layer_child.unwrap().with_common |common| {
                 current_layer_child = common.next_sibling;
             }
             self.root_layer.remove_child(trash);
         }
 
         // Add child layers.
-        for self.children.mut_iter().filter(|x| !x.child.hidden).advance |child| {
+        for child in self.children.mut_iter().filter(|x| !x.child.hidden) {
             current_layer_child = match current_layer_child {
                 None => {
                     child.container.common.parent = None;
@@ -295,7 +295,7 @@ impl CompositorLayer {
         };
 
         let all_tiles = quadtree.get_all_tiles();
-        for all_tiles.iter().advance |buffer| {
+        for buffer in all_tiles.iter() {
             debug!("osmain: compositing buffer rect %?", &buffer.rect);
             
             // Find or create a texture layer.
@@ -313,7 +313,7 @@ impl CompositorLayer {
                     texture_layer.manager = @buffer.draw_target.clone() as @TextureManager;
                     
                     // Move on to the next sibling.
-                    do current_layer_child.get().with_common |common| {
+                    do current_layer_child.unwrap().with_common |common| {
                         common.next_sibling
                     }
                 }
@@ -339,7 +339,7 @@ impl CompositorLayer {
                     Tree(ref mut quadtree) => quadtree,
                 };
                 
-                for new_buffers.buffers.iter().advance |buffer| {
+                for buffer in new_buffers.buffers.iter() {
                     // TODO: This may return old buffers, which should be sent back to the renderer.
                     quadtree.add_tile_pixel(buffer.screen_pos.origin.x, buffer.screen_pos.origin.y,
                                             buffer.resolution, ~buffer.clone());
@@ -349,7 +349,7 @@ impl CompositorLayer {
             return true;
         }
         // ID does not match ours, so recurse on descendents (including hidden children).
-        self.children.mut_iter().transform(|x| &mut x.child).any(|x| x.add_buffers(pipeline_id, new_buffers))
+        self.children.mut_iter().map(|x| &mut x.child).any(|x| x.add_buffers(pipeline_id, new_buffers))
     }
 
     // Deletes a specified sublayer, including hidden children. Returns false if the layer is not found.
@@ -362,7 +362,7 @@ impl CompositorLayer {
                 true
             }
             None => {
-                self.children.mut_iter().transform(|x| &mut x.child).any(|x| x.delete(pipeline_id))
+                self.children.mut_iter().map(|x| &mut x.child).any(|x| x.delete(pipeline_id))
             }
         }
     }
diff --git a/src/components/main/compositing/mod.rs b/src/components/main/compositing/mod.rs
index b8f4c22ae5d..6417e8128f4 100644
--- a/src/components/main/compositing/mod.rs
+++ b/src/components/main/compositing/mod.rs
@@ -20,15 +20,12 @@ use gfx::opts::Opts;
 
 use azure::azure_hl::{DataSourceSurface, DrawTarget, SourceSurfaceMethods, current_gl_context};
 use azure::azure::AzGLContext;
-use std::cell::Cell;
 use std::comm;
 use std::comm::{Chan, SharedChan, Port};
 use std::num::Orderable;
-use std::task;
-use std::uint;
 use std::vec;
-use extra::uv_global_loop;
-use extra::timer;
+use std::rt::rtio::RtioTimer;
+use std::rt::io::timer::Timer;
 use geom::matrix::identity;
 use geom::point::Point2D;
 use geom::size::Size2D;
@@ -80,7 +77,7 @@ impl RenderListener for CompositorChan {
         port.recv()
     }
 
-    fn paint(&self, id: PipelineId, layer_buffer_set: arc::ARC<LayerBufferSet>) {
+    fn paint(&self, id: PipelineId, layer_buffer_set: arc::Arc<LayerBufferSet>) {
         self.chan.send(Paint(id, layer_buffer_set))
     }
 
@@ -136,7 +133,7 @@ pub enum Msg {
     DeleteLayer(PipelineId),
 
     /// Requests that the compositor paint the given layer buffer set for the given page size.
-    Paint(PipelineId, arc::ARC<LayerBufferSet>),
+    Paint(PipelineId, arc::Arc<LayerBufferSet>),
     /// Alerts the compositor to the current status of page loading.
     ChangeReadyState(ReadyState),
     /// Alerts the compositor to the current status of rendering.
@@ -192,24 +189,7 @@ impl CompositorTask {
     }
 
     /// Starts the compositor, which listens for messages on the specified port. 
-    pub fn create(opts: Opts,
-                  port: Port<Msg>,
-                  profiler_chan: ProfilerChan,
-                  shutdown_chan: Chan<()>) {
-        let port = Cell::new(port);
-        let shutdown_chan = Cell::new(shutdown_chan);
-        let opts = Cell::new(opts);
-        do on_osmain {
-            let compositor_task = CompositorTask::new(opts.take(),
-                                                      port.take(),
-                                                      profiler_chan.clone(),
-                                                      shutdown_chan.take());
-            debug!("preparing to enter main loop");
-            compositor_task.run_main_loop();
-        };
-    }
-
-    fn run_main_loop(&self) {
+    pub fn run(&self) {
         let app: Application = ApplicationMethods::new();
         let window: @mut Window = WindowMethods::new(&app);
 
@@ -242,7 +222,7 @@ impl CompositorTask {
         let ask_for_tiles = || {
             let window_size_page = Size2D(window_size.width as f32 / world_zoom,
                                           window_size.height as f32 / world_zoom);
-            for compositor_layer.mut_iter().advance |layer| {
+            for layer in compositor_layer.mut_iter() {
                 recomposite = layer.get_buffer_request(Rect(Point2D(0f32, 0f32), window_size_page),
                                                        world_zoom) || recomposite;
             }
@@ -368,7 +348,7 @@ impl CompositorTask {
                         MouseWindowMouseDownEvent(_, p) => Point2D(p.x / world_zoom, p.y / world_zoom),
                         MouseWindowMouseUpEvent(_, p) => Point2D(p.x / world_zoom, p.y / world_zoom),
                     };
-                    for compositor_layer.iter().advance |layer| {
+                    for layer in compositor_layer.iter() {
                         layer.send_mouse_event(mouse_window_event, point);
                     }
                 }
@@ -380,7 +360,7 @@ impl CompositorTask {
                                                             cursor.y as f32 / world_zoom);
                     let page_window = Size2D(window_size.width as f32 / world_zoom,
                                              window_size.height as f32 / world_zoom);
-                    for compositor_layer.mut_iter().advance |layer| {
+                    for layer in compositor_layer.mut_iter() {
                         recomposite = layer.scroll(page_delta, page_cursor, page_window) || recomposite;
                     }
                     ask_for_tiles();
@@ -402,7 +382,7 @@ impl CompositorTask {
                     let page_cursor = Point2D(-1f32, -1f32); // Make sure this hits the base layer
                     let page_window = Size2D(window_size.width as f32 / world_zoom,
                                              window_size.height as f32 / world_zoom);
-                    for compositor_layer.mut_iter().advance |layer| {
+                    for layer in compositor_layer.mut_iter() {
                         layer.scroll(page_delta, page_cursor, page_window);
                     }
 
@@ -458,7 +438,7 @@ impl CompositorTask {
                 // flip image vertically (texture is upside down)
                 let orig_pixels = pixels.clone();
                 let stride = width * 3;
-                for uint::range(0, height) |y| {
+                for y in range(0, height) {
                     let dst_start = y * stride;
                     let src_start = (height - y - 1) * stride;
                     vec::bytes::copy_memory(pixels.mut_slice(dst_start, dst_start + stride),
@@ -483,6 +463,7 @@ impl CompositorTask {
         };
 
         // Enter the main event loop.
+        let tm = Timer::new().unwrap();
         while !done {
             // Check for new messages coming from the rendering task.
             check_for_messages(&self.port);
@@ -495,7 +476,7 @@ impl CompositorTask {
                 composite();
             }
 
-            timer::sleep(&uv_global_loop::get(), 10);
+            tm.sleep(10);
 
             // If a pinch-zoom happened recently, ask for tiles at the new resolution
             if zoom_action && precise_time_s() - zoom_time > 0.3 {
@@ -508,14 +489,3 @@ impl CompositorTask {
         self.shutdown_chan.send(())
     }
 }
-
-/// A function for spawning into the platform's main thread.
-fn on_osmain(f: ~fn()) {
-    // FIXME: rust#6399
-    let mut main_task = task::task();
-    main_task.sched_mode(task::PlatformThread);
-    do main_task.spawn {
-        f();
-    }
-}
-
diff --git a/src/components/main/compositing/quadtree.rs b/src/components/main/compositing/quadtree.rs
index 7fc7a72657f..d58f568694d 100644
--- a/src/components/main/compositing/quadtree.rs
+++ b/src/components/main/compositing/quadtree.rs
@@ -47,7 +47,7 @@ struct QuadtreeNode<T> {
     tile_mem: uint,
 }
 
-priv enum Quadrant {
+enum Quadrant {
     TL = 0,
     TR = 1,
     BL = 2,
@@ -212,7 +212,7 @@ impl<T: Tile> Quadtree<T> {
         let difference = (new_size as f32 / self.root.size as f32).log2() as int;
         if difference > 0 { // doubling
             let difference = difference as uint;
-            for range(0, difference) |i| {
+            for i in range(0, difference) {
                 let new_root = ~QuadtreeNode {
                     tile: None,
                     origin: Point2D(0f32, 0f32),
@@ -225,7 +225,7 @@ impl<T: Tile> Quadtree<T> {
             }
         } else if difference < 0 { // halving
             let difference = difference.abs() as uint;
-            for difference.times {
+            for _ in range(0, difference) {
                 let remove = replace(&mut self.root.quadrants[TL as int], None);
                 match remove {
                     Some(child) => self.root = child,
@@ -299,7 +299,7 @@ impl<T: Tile> QuadtreeNode<T> {
     fn get_all_tiles<'r>(&'r self) -> ~[&'r T] {
         let mut ret = ~[];
 
-        for self.quadrants.iter().advance |quad| {
+        for quad in self.quadrants.iter() {
             match *quad {
                 Some(ref child) => ret = ret + child.get_all_tiles(),
                 None => {}
@@ -332,7 +332,7 @@ impl<T: Tile> QuadtreeNode<T> {
             self.tile = Some(tile);
             // FIXME: This should be inline, but currently won't compile
             let quads = [TL, TR, BL, BR];
-            for quads.iter().advance |quad| {
+            for quad in quads.iter() {
                 self.quadrants[*quad as int] = None;
             }
             self.render_flag = false;
@@ -439,7 +439,7 @@ impl<T: Tile> QuadtreeNode<T> {
         let mut del_quad: Option<Quadrant> = None;
         let mut ret = (None, false, 0);
         
-        for queue.iter().advance |quad| {
+        for quad in queue.iter() {
             match self.quadrants[*quad as int] {
                 Some(ref mut child) => {
                     let (tile, flag, delta) = child.remove_tile(x, y);
@@ -514,7 +514,7 @@ impl<T: Tile> QuadtreeNode<T> {
                         let old_mem = self.tile_mem;
                         // FIXME: This should be inline, but currently won't compile
                         let quads = [TL, TR, BL, BR];
-                        for quads.iter().advance |quad| {
+                        for quad in quads.iter() {
                             self.quadrants[*quad as int] = None;
                         }
                         self.tile_mem = tile.get_mem();
@@ -561,7 +561,7 @@ impl<T: Tile> QuadtreeNode<T> {
         let mut redisplay = false;
         let mut delta = 0;
         
-        for quads_to_check.iter().advance |quad| {
+        for quad in quads_to_check.iter() {
             // Recurse into child
             let new_window = match *quad {
                 TL => Rect(window.origin,
@@ -628,7 +628,7 @@ impl<T: Tile> QuadtreeNode<T> {
                 ret = fmt!("%s<table border=1><tr>", ret);
                 // FIXME: This should be inline, but currently won't compile
                 let quads = [TL, TR, BL, BR];
-                for quads.iter().advance |quad| {
+                for quad in quads.iter() {
                     match self.quadrants[*quad as int] {
                         Some(ref child) => {
                             ret = fmt!("%s<td>%s</td>", ret, child.get_html());
diff --git a/src/components/main/constellation.rs b/src/components/main/constellation.rs
index d1ae44f7bfe..32da23206b0 100644
--- a/src/components/main/constellation.rs
+++ b/src/components/main/constellation.rs
@@ -4,8 +4,6 @@
 
 use compositing::{CompositorChan, SetIds};
 
-use extra::net::url;
-
 use std::cell::Cell;
 use std::comm;
 use std::comm::Port;
@@ -51,7 +49,7 @@ struct FrameTree {
 // Need to clone the FrameTrees, but _not_ the Pipelines
 impl Clone for FrameTree {
     fn clone(&self) -> FrameTree {
-        let mut children = do self.children.iter().transform |&frame_tree| {
+        let mut children = do self.children.iter().map |&frame_tree| {
             @mut (*frame_tree).clone()
         };
         FrameTree {
@@ -95,27 +93,27 @@ impl FrameTree {
 
     /// Replaces a node of the frame tree in place. Returns the node that was removed or the original node
     /// if the node to replace could not be found.
-    fn replace_child(&mut self, id: PipelineId, new_child: @mut FrameTree) -> Result<@mut FrameTree, @mut FrameTree> {
+    fn replace_child(&mut self, id: PipelineId, new_child: @mut FrameTree) -> Either<@mut FrameTree, @mut FrameTree> {
         let new_child_cell = Cell::new(new_child);
-        for self.children.mut_iter().advance |child| {
+        for child in self.children.mut_iter() {
             let new_child = new_child_cell.take();
             if child.pipeline.id == id {
                 new_child.parent = child.parent;
-                return Ok(replace(child, new_child));
+                return Left(replace(child, new_child));
             } 
             let replaced = child.replace_child(id, new_child);
-            if replaced.is_ok() {
+            if replaced.is_left() {
                 return replaced;
             }
-            new_child_cell.put_back(replaced.get_err());
+            new_child_cell.put_back(replaced.unwrap_right());
         }
-        Err(new_child_cell.take())
+        Right(new_child_cell.take())
     }
 
     fn to_sendable(&self) -> SendableFrameTree {
         let sendable_frame_tree = SendableFrameTree {
             pipeline: (*self.pipeline).clone(),
-            children: self.children.iter().transform(|frame_tree| frame_tree.to_sendable()).collect(),
+            children: self.children.iter().map(|frame_tree| frame_tree.to_sendable()).collect(),
         };
         sendable_frame_tree
     }
@@ -169,17 +167,17 @@ impl NavigationContext {
      * when it is known that there exists either a previous page or a next page. */
 
     pub fn back(&mut self) -> @mut FrameTree {
-        self.next.push(self.current.swap_unwrap());
+        self.next.push(self.current.take_unwrap());
         self.current = Some(self.previous.pop());
         debug!("previous: %? next: %? current: %?", self.previous, self.next, *self.current.get_ref());
-        self.current.get()
+        self.current.unwrap()
     }
 
     pub fn forward(&mut self) -> @mut FrameTree {
-        self.previous.push(self.current.swap_unwrap());
+        self.previous.push(self.current.take_unwrap());
         self.current = Some(self.next.pop());
         debug!("previous: %? next: %? current: %?", self.previous, self.next, *self.current.get_ref());
-        self.current.get()
+        self.current.unwrap()
     }
 
     /// Loads a new set of page frames, returning all evicted frame trees
@@ -187,7 +185,7 @@ impl NavigationContext {
         debug!("navigating to %?", frame_tree);
         let evicted = replace(&mut self.next, ~[]);
         if self.current.is_some() {
-            self.previous.push(self.current.swap_unwrap());
+            self.previous.push(self.current.take_unwrap());
         }
         self.current = Some(frame_tree);
         evicted
@@ -204,7 +202,7 @@ impl NavigationContext {
         let from_prev = do self.previous.iter().filter_map |frame_tree| {
             frame_tree.find_mut(pipeline_id)
         };
-        from_prev.chain_(from_current).chain_(from_next).collect()
+        from_prev.chain(from_current).chain(from_next).collect()
     }
 
     pub fn contains(&mut self, pipeline_id: PipelineId) -> bool {
@@ -212,7 +210,7 @@ impl NavigationContext {
         let from_next = self.next.iter();
         let from_prev = self.previous.iter();
 
-        let mut all_contained = from_prev.chain_(from_current).chain_(from_next);
+        let mut all_contained = from_prev.chain(from_current).chain(from_next);
         do all_contained.any |frame_tree| {
             frame_tree.contains(pipeline_id)
         }
@@ -227,7 +225,7 @@ impl Constellation {
                  profiler_chan: ProfilerChan)
                  -> ConstellationChan {
             
-        let opts = Cell::new(copy *opts);
+        let opts = Cell::new((*opts).clone());
 
         let (constellation_port, constellation_chan) = special_stream!(ConstellationChan);
         let constellation_port = Cell::new(constellation_port);
@@ -285,7 +283,7 @@ impl Constellation {
         match request {
 
             ExitMsg(sender) => {
-                for self.pipelines.iter().advance |(_id, ref pipeline)| {
+                for (_id, ref pipeline) in self.pipelines.iter() {
                     pipeline.exit();
                 }
                 self.image_cache_task.exit();
@@ -304,7 +302,7 @@ impl Constellation {
                                                      self.image_cache_task.clone(),
                                                      self.resource_task.clone(),
                                                      self.profiler_chan.clone(),
-                                                     copy self.opts,
+                                                     self.opts.clone(),
                                                      {
                                                          let size = self.compositor_chan.get_size();
                                                          from_value(Size2D(size.width as uint, size.height as uint))
@@ -339,7 +337,7 @@ impl Constellation {
                     let matching_pending_frames = do self.pending_frames.iter().filter_map |frame_change| {
                         frame_change.after.find_mut(source_pipeline_id)
                     };
-                    matching_navi_frames.consume_iter().chain_(matching_pending_frames).collect()
+                    matching_navi_frames.move_iter().chain(matching_pending_frames).collect()
                 };
 
                 if frame_trees.is_empty() {
@@ -370,7 +368,7 @@ impl Constellation {
                                           self.compositor_chan.clone(),
                                           self.image_cache_task.clone(),
                                           self.profiler_chan.clone(),
-                                          copy self.opts,
+                                          self.opts.clone(),
                                           source_pipeline,
                                           size_future)
                 } else {
@@ -382,7 +380,7 @@ impl Constellation {
                                      self.image_cache_task.clone(),
                                      self.resource_task.clone(),
                                      self.profiler_chan.clone(),
-                                     copy self.opts,
+                                     self.opts.clone(),
                                      size_future)
                 };
 
@@ -391,7 +389,7 @@ impl Constellation {
                 } else {
                     pipeline.load(url, None);
                 }
-                for frame_trees.iter().advance |frame_tree| {
+                for frame_tree in frame_trees.iter() {
                     frame_tree.children.push(@mut FrameTree {
                         pipeline: pipeline,
                         parent: Some(source_pipeline),
@@ -405,14 +403,14 @@ impl Constellation {
             // If there is already a pending page (self.pending_frames), it will not be overridden;
             // However, if the id is not encompassed by another change, it will be.
             LoadUrlMsg(source_id, url, size_future) => {
-                debug!("received message to load %s", url::to_str(&url));
+                debug!("received message to load %s", url.to_str());
                 // Make sure no pending page would be overridden.
                 let source_frame = self.current_frame().get_ref().find_mut(source_id).expect(
                     "Constellation: received a LoadUrlMsg from a pipeline_id associated
                     with a pipeline not in the active frame tree. This should be
                     impossible.");
 
-                for self.pending_frames.iter().advance |frame_change| {
+                for frame_change in self.pending_frames.iter() {
                     let old_id = frame_change.before.expect("Constellation: Received load msg
                         from pipeline, but there is no currently active page. This should
                         be impossible.");
@@ -438,7 +436,7 @@ impl Constellation {
                                                      self.image_cache_task.clone(),
                                                      self.resource_task.clone(),
                                                      self.profiler_chan.clone(),
-                                                     copy self.opts,
+                                                     self.opts.clone(),
                                                      size_future);
 
                 if url.path.ends_with(".js") {
@@ -473,7 +471,7 @@ impl Constellation {
                             return true
                         } else {
                             let old = self.current_frame().get_ref();
-                            for old.iter().advance |frame| {
+                            for frame in old.iter() {
                                 frame.pipeline.revoke_paint_permission();
                             }
                         }
@@ -485,7 +483,7 @@ impl Constellation {
                             return true
                         } else {
                             let old = self.current_frame().get_ref();
-                            for old.iter().advance |frame| {
+                            for frame in old.iter() {
                                 frame.pipeline.revoke_paint_permission();
                             }
                         }
@@ -493,7 +491,7 @@ impl Constellation {
                     }
                 };
 
-                for destination_frame.iter().advance |frame| {
+                for frame in destination_frame.iter() {
                     let pipeline = &frame.pipeline;
                     pipeline.reload(Some(constellation_msg::Navigate));
                 }
@@ -507,7 +505,7 @@ impl Constellation {
                 // from a pending frame. The only time that we will grant paint permission is
                 // when the message originates from a pending frame or the current frame.
 
-                for self.current_frame().iter().advance |&current_frame| {
+                for &current_frame in self.current_frame().iter() {
                     // Messages originating in the current frame are not navigations;
                     // TODO(tkuehn): In fact, this kind of message might be provably
                     // impossible to occur.
@@ -523,26 +521,26 @@ impl Constellation {
                 let pending_index = do self.pending_frames.rposition |frame_change| {
                     frame_change.after.pipeline.id == pipeline_id
                 };
-                for pending_index.iter().advance |&pending_index| {
+                for &pending_index in pending_index.iter() {
                     let frame_change = self.pending_frames.swap_remove(pending_index);
                     let to_add = frame_change.after;
 
                     // Create the next frame tree that will be given to the compositor
                     let next_frame_tree = match to_add.parent {
                         None => to_add, // to_add is the root
-                        Some(_parent) => @mut (*self.current_frame().get()).clone(),
+                        Some(_parent) => @mut (*self.current_frame().unwrap()).clone(),
                     };
 
                     // If there are frames to revoke permission from, do so now.
                     match frame_change.before {
                         Some(revoke_id) => {
-                            let current_frame = self.current_frame().get();
+                            let current_frame = self.current_frame().unwrap();
 
                             let to_revoke = current_frame.find_mut(revoke_id).expect(
                                 "Constellation: pending frame change refers to an old
                                 frame not contained in the current frame. This is a bug");
 
-                            for to_revoke.iter().advance |frame| {
+                            for frame in to_revoke.iter() {
                                 frame.pipeline.revoke_paint_permission();
                             }
 
@@ -556,7 +554,7 @@ impl Constellation {
                             // Add to_add to parent's children, if it is not the root
                             let parent = &to_add.parent;
                             let to_add = Cell::new(to_add);
-                            for parent.iter().advance |parent| {
+                            for parent in parent.iter() {
                                 let parent = next_frame_tree.find_mut(parent.id).expect(
                                     "Constellation: pending frame has a parent frame that is not
                                     active. This is a bug.");
@@ -571,13 +569,13 @@ impl Constellation {
             ResizedWindowBroadcast(new_size) => match *self.current_frame() {
                 Some(ref current_frame) => {
                     let current_frame_id = current_frame.pipeline.id.clone();
-                    for self.navigation_context.previous.iter().advance |frame_tree| {
+                    for frame_tree in self.navigation_context.previous.iter() {
                         let pipeline = &frame_tree.pipeline;
                         if current_frame_id != pipeline.id {
                             pipeline.script_chan.send(ResizeInactiveMsg(new_size));
                         }
                     }
-                    for self.navigation_context.next.iter().advance |frame_tree| {
+                    for frame_tree in self.navigation_context.next.iter() {
                         let pipeline = &frame_tree.pipeline;
                         if current_frame_id != pipeline.id {
                             pipeline.script_chan.send(ResizeInactiveMsg(new_size));
@@ -585,10 +583,10 @@ impl Constellation {
                     }
                 }
                 None => {
-                    for self.navigation_context.previous.iter().advance |frame_tree| {
+                    for frame_tree in self.navigation_context.previous.iter() {
                         frame_tree.pipeline.script_chan.send(ResizeInactiveMsg(new_size));
                     }
-                    for self.navigation_context.next.iter().advance |frame_tree| {
+                    for frame_tree in self.navigation_context.next.iter() {
                         frame_tree.pipeline.script_chan.send(ResizeInactiveMsg(new_size));
                     }
                 }
@@ -608,9 +606,9 @@ impl Constellation {
         match frame_tree.pipeline.navigation_type {
             Some(constellation_msg::Load) => {
                 let evicted = self.navigation_context.load(frame_tree);
-                for evicted.iter().advance |frame_tree| {
+                for frame_tree in evicted.iter() {
                     // exit any pipelines that don't exist outside the evicted frame trees
-                    for frame_tree.iter().advance |frame| {
+                    for frame in frame_tree.iter() {
                         if !self.navigation_context.contains(frame.pipeline.id) {
                             frame_tree.pipeline.exit();
                             self.pipelines.remove(&frame_tree.pipeline.id);
@@ -626,7 +624,7 @@ impl Constellation {
         let (port, chan) = comm::stream();
         self.compositor_chan.send(SetIds(frame_tree.to_sendable(), chan));
         port.recv();
-        for frame_tree.iter().advance |frame| {
+        for frame in frame_tree.iter() {
             frame.pipeline.grant_paint_permission();
         }
     }
diff --git a/src/components/main/css/matching.rs b/src/components/main/css/matching.rs
index b1712d286eb..f78f8c51ecd 100644
--- a/src/components/main/css/matching.rs
+++ b/src/components/main/css/matching.rs
@@ -11,7 +11,7 @@ use layout::incremental;
 use script::dom::node::{AbstractNode, LayoutView};
 use newcss::complete::CompleteSelectResults;
 use newcss::select::{SelectCtx, SelectResults};
-use servo_util::tree::TreeUtils;
+use servo_util::tree::TreeNodeRef;
 
 pub trait MatchMethods {
     fn restyle_subtree(&self, select_ctx: &SelectCtx);
@@ -48,7 +48,7 @@ impl MatchMethods for AbstractNode<LayoutView> {
             };
         }
 
-        for self.each_child |kid| {
+        for kid in self.children() {
             kid.restyle_subtree(select_ctx); 
         }
     }
diff --git a/src/components/main/css/node_util.rs b/src/components/main/css/node_util.rs
index a63ee695af5..721b8ca9132 100644
--- a/src/components/main/css/node_util.rs
+++ b/src/components/main/css/node_util.rs
@@ -65,7 +65,7 @@ impl<'self> NodeUtil<'self> for AbstractNode<LayoutView> {
         if !self.has_layout_data() {
             return default;
         }
-        self.layout_data().restyle_damage.get_or_default(default)
+        self.layout_data().restyle_damage.unwrap_or_default(default)
     }
 
     /// Set the restyle damage field.
diff --git a/src/components/main/css/select.rs b/src/components/main/css/select.rs
index b776ade5978..d106c7bc6e9 100644
--- a/src/components/main/css/select.rs
+++ b/src/components/main/css/select.rs
@@ -2,10 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use extra::net::url::Url;
-use url_from_str = extra::net::url::from_str;
+use extra::url::Url;
 use std::cell::Cell;
-use std::result;
+use std::FromStr;
 use newcss::stylesheet::Stylesheet;
 use newcss::select::SelectCtx;
 use newcss::types::OriginUA;
@@ -29,7 +28,7 @@ fn servo_default_style() -> Stylesheet {
 }
 
 fn default_url(name: &str) -> Url {
-    result::unwrap(url_from_str(fmt!("http://%s", name)))
+    FromStr::from_str(fmt!("http://%s", name)).unwrap()
 }
 
 fn style_stream(style: &str) -> DataStream {
diff --git a/src/components/main/css/select_handler.rs b/src/components/main/css/select_handler.rs
index 4a294aa2426..e031b153b0f 100644
--- a/src/components/main/css/select_handler.rs
+++ b/src/components/main/css/select_handler.rs
@@ -101,7 +101,7 @@ impl SelectHandler<AbstractNode<LayoutView>> for NodeSelectHandler {
                 None => false,
                 Some(existing_classes) => {
                     let mut ret = false;
-                    for existing_classes.split_iter(' ').advance |s| {
+                    for s in existing_classes.split_iter(' ') {
                         if s == class {
                             ret = true;
                             break;
diff --git a/src/components/main/layout/aux.rs b/src/components/main/layout/aux.rs
index d63df74c53d..f49d73de913 100644
--- a/src/components/main/layout/aux.rs
+++ b/src/components/main/layout/aux.rs
@@ -9,7 +9,7 @@ use layout::incremental::RestyleDamage;
 
 use newcss::complete::CompleteSelectResults;
 use script::dom::node::{AbstractNode, LayoutView};
-use servo_util::tree::TreeUtils;
+use servo_util::tree::TreeNodeRef;
 
 /// Data that layout associates with a node.
 pub struct LayoutData {
@@ -37,7 +37,7 @@ impl LayoutData {
 /// Functionality useful for querying the layout-specific data on DOM nodes.
 pub trait LayoutAuxMethods {
     fn layout_data(self) -> @mut LayoutData;
-    pub fn has_layout_data(self) -> bool;
+    fn has_layout_data(self) -> bool;
     fn set_layout_data(self, data: @mut LayoutData);
 
     fn initialize_layout_data(self) -> Option<@mut LayoutData>;
@@ -45,17 +45,17 @@ pub trait LayoutAuxMethods {
 }
 
 impl LayoutAuxMethods for AbstractNode<LayoutView> {
-    pub fn layout_data(self) -> @mut LayoutData {
+    fn layout_data(self) -> @mut LayoutData {
         unsafe {
             self.unsafe_layout_data()
         }
     }
-    pub fn has_layout_data(self) -> bool {
+    fn has_layout_data(self) -> bool {
        unsafe {
             self.unsafe_has_layout_data()
         }
     }
-    pub fn set_layout_data(self, data: @mut LayoutData) {
+    fn set_layout_data(self, data: @mut LayoutData) {
         unsafe {
             self.unsafe_set_layout_data(data)
         }
@@ -84,7 +84,7 @@ impl LayoutAuxMethods for AbstractNode<LayoutView> {
     /// Initializes layout data and styles for a Node tree, if any nodes do not have
     /// this data already. Append created layout data to the task's GC roots.
     fn initialize_style_for_subtree(self, refs: &mut ~[@mut LayoutData]) {
-        let _ = for self.traverse_preorder |n| {
+        let _ = for n in self.traverse_preorder() {
             match n.initialize_layout_data() {
                 Some(r) => refs.push(r),
                 None => {}
diff --git a/src/components/main/layout/block.rs b/src/components/main/layout/block.rs
index e78bc87f158..b30794a0343 100644
--- a/src/components/main/layout/block.rs
+++ b/src/components/main/layout/block.rs
@@ -18,7 +18,7 @@ use geom::rect::Rect;
 use gfx::display_list::DisplayList;
 use gfx::geometry::Au;
 use gfx::geometry;
-use servo_util::tree::{TreeNodeRef, TreeUtils};
+use servo_util::tree::TreeNodeRef;
 
 pub struct BlockFlowData {
     /// Data common to all flows.
@@ -50,7 +50,7 @@ impl BlockFlowData {
 
     pub fn teardown(&mut self) {
         self.common.teardown();
-        for self.box.iter().advance |box| {
+        for box in self.box.iter() {
             box.teardown();
         }
         self.box = None;
@@ -94,7 +94,7 @@ impl BlockFlowData {
         let mut num_floats = 0;
 
         /* find max width from child block contexts */
-        for BlockFlow(self).each_child |child_ctx| {
+        for child_ctx in BlockFlow(self).children() {
             assert!(child_ctx.starts_block_flow() || child_ctx.starts_inline_flow());
 
             do child_ctx.with_mut_base |child_node| {
@@ -124,7 +124,7 @@ impl BlockFlowData {
  
     /// Computes left and right margins and width based on CSS 2.1 secion 10.3.3.
     /// Requires borders and padding to already be computed
-    priv fn compute_horiz( &self, 
+    fn compute_horiz( &self,
                             width: MaybeAuto, 
                             left_margin: MaybeAuto, 
                             right_margin: MaybeAuto, 
@@ -192,7 +192,7 @@ impl BlockFlowData {
         let mut remaining_width = self.common.position.size.width;
         let mut x_offset = Au(0);
 
-        for self.box.iter().advance |&box| {
+        for &box in self.box.iter() {
             let style = box.style();
             do box.with_model |model| {
                 // Can compute padding here since we know containing block width.
@@ -239,7 +239,7 @@ impl BlockFlowData {
         }
 
         let has_inorder_children = self.common.is_inorder || self.common.num_floats > 0;
-        for BlockFlow(self).each_child |kid| {
+        for kid in BlockFlow(self).children() {
             assert!(kid.starts_block_flow() || kid.starts_inline_flow());
 
             do kid.with_mut_base |child_node| {
@@ -278,7 +278,7 @@ impl BlockFlowData {
         let mut left_offset = Au(0);
         let mut float_ctx = Invalid;
 
-        for self.box.iter().advance |&box| {
+        for &box in self.box.iter() {
             clearance = match box.clear() {
                 None => Au(0),
                 Some(clear) => {
@@ -303,7 +303,7 @@ impl BlockFlowData {
             // repeat until all children are visited.
             // last_child.floats_out -> self.floats_out (done at the end of this method)
             float_ctx = self.common.floats_in.translate(Point2D(-left_offset, -top_offset));
-            for BlockFlow(self).each_child |kid| {
+            for kid in BlockFlow(self).children() {
                 do kid.with_mut_base |child_node| {
                     child_node.floats_in = float_ctx.clone();
                 }
@@ -311,10 +311,9 @@ impl BlockFlowData {
                 do kid.with_mut_base |child_node| {
                     float_ctx = child_node.floats_out.clone();
                 }
-
             }
         }
-        for BlockFlow(self).each_child |kid| {
+        for kid in BlockFlow(self).children() {
             do kid.with_mut_base |child_node| {
                 child_node.position.origin.y = cur_y;
                 cur_y = cur_y + child_node.position.size.height;
@@ -327,7 +326,7 @@ impl BlockFlowData {
             cur_y - top_offset
         };
 
-        for self.box.iter().advance |&box| {
+        for &box in self.box.iter() {
             let style = box.style();
             let maybe_height = MaybeAuto::from_height(style.height(), Au(0), style.font_size());
             let maybe_height = maybe_height.specified_or_zero();
@@ -380,7 +379,7 @@ impl BlockFlowData {
 
         // go deeper into the flow tree
         let flow = BlockFlow(self);
-        for flow.each_child |child| {
+        for child in flow.children() {
             do child.with_mut_base |base| {
                 base.abs_position = self.common.abs_position + base.position.origin;
             }
diff --git a/src/components/main/layout/box.rs b/src/components/main/layout/box.rs
index f9b63ed65ed..ac37c30d9a8 100644
--- a/src/components/main/layout/box.rs
+++ b/src/components/main/layout/box.rs
@@ -16,7 +16,6 @@ use std::cell::Cell;
 use std::cmp::ApproxEq;
 use std::managed;
 use std::num::Zero;
-use std::uint;
 use geom::{Point2D, Rect, Size2D, SideOffsets2D};
 use gfx::display_list::{BaseDisplayItem, BorderDisplayItem, BorderDisplayItemClass};
 use gfx::display_list::{DisplayList, ImageDisplayItem, ImageDisplayItemClass};
@@ -38,7 +37,7 @@ use script::dom::node::{AbstractNode, LayoutView};
 use servo_net::image::holder::ImageHolder;
 use servo_net::local_image_cache::LocalImageCache;
 use servo_util::range::*;
-use extra::net::url::Url;
+use extra::url::Url;
 
 /// Render boxes (`struct RenderBox`) are the leaves of the layout tree. They cannot position
 /// themselves. In general, render boxes do not have a simple correspondence with CSS boxes as in
@@ -292,14 +291,13 @@ impl RenderBox {
                        text_box.range,
                        max_width);
 
-                for text_box.run.iter_slices_for_range(&text_box.range)
-                                                        |glyphs, offset, slice_range| {
+                for (glyphs, offset, slice_range) in text_box.run.iter_slices_for_range(&text_box.range) {
                     debug!("split_to_width: considering slice (offset=%?, range=%?, remain_width=%?)",
                            offset,
                            slice_range,
                            remaining_width);
 
-                    let metrics = text_box.run.metrics_for_slice(glyphs, slice_range);
+                    let metrics = text_box.run.metrics_for_slice(glyphs, &slice_range);
                     let advance = metrics.advance_width;
                     let should_continue: bool;
 
@@ -385,7 +383,7 @@ impl RenderBox {
     //
     // TODO(eatkinson): integrate with
     // get_min_width and get_pref_width?
-    priv fn guess_width (&self) -> Au {
+    fn guess_width (&self) -> Au {
         do self.with_base |base| {
             if(!base.node.is_element()) {
                 Au(0)
@@ -433,7 +431,7 @@ impl RenderBox {
             ImageRenderBoxClass(image_box) => {
                 // TODO: Consult the CSS `width` property as well as margins and borders.
                 // TODO: If the image isn't available, consult `width`.
-                Au::from_px(image_box.image.get_size().get_or_default(Size2D(0, 0)).width)
+                Au::from_px(image_box.image.get_size().unwrap_or_default(Size2D(0, 0)).width)
             }
 
             TextRenderBoxClass(text_box) => {
@@ -454,7 +452,7 @@ impl RenderBox {
             GenericRenderBoxClass(*) => Au(0),
 
             ImageRenderBoxClass(image_box) => {
-                Au::from_px(image_box.image.get_size().get_or_default(Size2D(0, 0)).width)
+                Au::from_px(image_box.image.get_size().unwrap_or_default(Size2D(0, 0)).width)
             }
 
             TextRenderBoxClass(text_box) => {
@@ -465,9 +463,8 @@ impl RenderBox {
                 // report nothing and the parent flow can factor in minimum/preferred widths of any
                 // text runs that it owns.
                 let mut max_line_width = Au(0);
-                for text_box.run.iter_natural_lines_for_range(&text_box.range)
-                        |line_range| {
-                    let line_metrics = text_box.run.metrics_for_range(line_range);
+                for line_range in text_box.run.iter_natural_lines_for_range(&text_box.range) {
+                    let line_metrics = text_box.run.metrics_for_range(&line_range);
                     max_line_width = Au::max(max_line_width, line_metrics.advance_width);
                 }
 
@@ -782,7 +779,7 @@ impl RenderBox {
         // FIXME: Too much allocation here.
         let font_families = do my_style.font_family().map |family| {
             match *family {
-                CSSFontFamilyFamilyName(ref family_str) => copy *family_str,
+                CSSFontFamilyFamilyName(ref family_str) => (*family_str).clone(),
                 CSSFontFamilyGenericFamily(Serif)       => ~"serif",
                 CSSFontFamilyGenericFamily(SansSerif)   => ~"sans-serif",
                 CSSFontFamilyGenericFamily(Cursive)     => ~"cursive",
@@ -823,7 +820,7 @@ impl RenderBox {
         self.nearest_ancestor_element().style().text_align()
     }
 
-    fn line_height(&self) -> CSSLineHeight {
+    pub fn line_height(&self) -> CSSLineHeight {
         self.nearest_ancestor_element().style().line_height()
     }
 
@@ -875,7 +872,7 @@ impl RenderBox {
     /// Dumps a render box for debugging, with indentation.
     pub fn dump_indent(&self, indent: uint) {
         let mut string = ~"";
-        for uint::range(0u, indent) |_i| {
+        for _ in range(0u, indent) {
             string.push_str("    ");
         }
 
diff --git a/src/components/main/layout/box_builder.rs b/src/components/main/layout/box_builder.rs
index 643a7b80b5d..3e7cd563206 100644
--- a/src/components/main/layout/box_builder.rs
+++ b/src/components/main/layout/box_builder.rs
@@ -30,7 +30,7 @@ use script::dom::element::*;
 use script::dom::node::{AbstractNode, CommentNodeTypeId, DoctypeNodeTypeId};
 use script::dom::node::{ElementNodeTypeId, LayoutView, TextNodeTypeId};
 use servo_util::range::Range;
-use servo_util::tree::{TreeNodeRef, TreeNode, TreeUtils};
+use servo_util::tree::{TreeNodeRef, TreeNode};
 
 pub struct LayoutTreeBuilder {
     root_flow: Option<FlowContext>,
@@ -60,7 +60,7 @@ enum InlineSpacerSide {
     LogicalAfter,
 }
 
-priv fn simulate_UA_display_rules(node: AbstractNode<LayoutView>) -> CSSDisplay {
+fn simulate_UA_display_rules(node: AbstractNode<LayoutView>) -> CSSDisplay {
     // FIXME
     /*let resolved = do node.aux |nd| {
         match nd.style.display_type {
@@ -145,8 +145,7 @@ impl BoxGenerator {
                 } else if self.inline_spacers_needed_for_node(node) {
                     // else, maybe make a spacer for "left" margin, border, padding
                     let inline_spacer = self.make_inline_spacer_for_node_side(ctx, node, LogicalBefore);
-                    for inline_spacer.iter().advance
-                            |spacer: &RenderBox| {
+                    for spacer in inline_spacer.iter() {
                         inline.boxes.push(*spacer);
                     }
                 }
@@ -220,7 +219,7 @@ impl BoxGenerator {
                     // If this non-leaf box generates extra horizontal spacing, add a SpacerBox for
                     // it.
                     let result = self.make_inline_spacer_for_node_side(ctx, node, LogicalAfter);
-                    for result.iter().advance |spacer| {
+                    for spacer in result.iter() {
                         let boxes = &mut self.flow.inline().boxes;
                         boxes.push(*spacer);
                     }
@@ -269,7 +268,7 @@ impl BoxGenerator {
         do node.with_imm_image_element |image_element| {
             if image_element.image.is_some() {
                 // FIXME(pcwalton): Don't copy URLs.
-                let url = copy *image_element.image.get_ref();
+                let url = (*image_element.image.get_ref()).clone();
                 ImageRenderBoxClass(@mut ImageRenderBox::new(base, url, layout_ctx.image_cache))
             } else {
                 info!("Tried to make image box, but couldn't find image. Made generic box \
@@ -328,7 +327,7 @@ impl LayoutTreeBuilder {
 
         // recurse on child nodes.
         let mut prev_generator: Option<@mut BoxGenerator> = None;
-        for cur_node.each_child |child_node| {
+        for child_node in cur_node.children() {
             prev_generator = self.construct_recursively(layout_ctx, child_node, this_generator, prev_generator);
         }
 
@@ -340,7 +339,7 @@ impl LayoutTreeBuilder {
         // eventually be elided or split, but the mapping between
         // nodes and FlowContexts should not change during layout.
         let flow: &FlowContext = &this_generator.flow;
-        for flow.each_child |child_flow| {
+        for child_flow in flow.children() {
             do child_flow.with_base |child_node| {
                 let dom_node = child_node.node;
                 assert!(dom_node.has_layout_data());
@@ -403,22 +402,22 @@ impl LayoutTreeBuilder {
             // Floats
             (CSSDisplayBlock, BlockFlow(_), _) |
             (CSSDisplayBlock, FloatFlow(_), _) if !is_float.is_none() => {
-                self.create_child_generator(node, parent_generator, Flow_Float(is_float.get()))
+                self.create_child_generator(node, parent_generator, Flow_Float(is_float.unwrap()))
             }
             // If we're placing a float after an inline, append the float to the inline flow,
             // then continue building from the inline flow in case there are more inlines
             // afterward.
             (CSSDisplayBlock, _, Some(InlineFlow(_))) if !is_float.is_none() => {
                 let float_generator = self.create_child_generator(node, 
-                                                                  sibling_generator.get(), 
-                                                                  Flow_Float(is_float.get()));
-                return Some((float_generator, sibling_generator.get()));
+                                                                  sibling_generator.unwrap(),
+                                                                  Flow_Float(is_float.unwrap()));
+                return Some((float_generator, sibling_generator.unwrap()));
             }
             // This is a catch-all case for when:
             // a) sibling_flow is None
             // b) sibling_flow is a BlockFlow
             (CSSDisplayBlock, InlineFlow(_), _) if !is_float.is_none() => {
-                self.create_child_generator(node, parent_generator, Flow_Float(is_float.get()))
+                self.create_child_generator(node, parent_generator, Flow_Float(is_float.unwrap()))
             }
 
             (CSSDisplayBlock, BlockFlow(info), _) => match (info.is_root, node.parent_node()) {
@@ -515,7 +514,7 @@ impl LayoutTreeBuilder {
                 let mut found_child_block = false;
 
                 let flow = *parent_flow;
-                for flow.each_child |child_ctx: FlowContext| {
+                for child_ctx in flow.children() {
                     match child_ctx {
                         InlineFlow(*) | InlineBlockFlow(*) => found_child_inline = true,
                         BlockFlow(*) => found_child_block = true,
@@ -535,7 +534,7 @@ impl LayoutTreeBuilder {
                 let first_child = do parent_flow.with_base |parent_node| {
                     parent_node.first_child
                 };
-                for first_child.iter().advance |&first_flow| {
+                for &first_flow in first_child.iter() {
                     if first_flow.starts_inline_flow() {
                         // FIXME: workaround for rust#6393
                         let mut do_remove = false;
@@ -558,7 +557,7 @@ impl LayoutTreeBuilder {
                 let last_child = do parent_flow.with_base |parent_node| {
                     parent_node.last_child
                 };
-                for last_child.iter().advance |&last_flow| {
+                for &last_flow in last_child.iter() {
                     if last_flow.starts_inline_flow() {
                         // FIXME: workaround for rust#6393
                         let mut do_remove = false;
@@ -580,7 +579,7 @@ impl LayoutTreeBuilder {
 
                 // Issue 543: We only need to do this if there are inline child
                 // flows, but there's not a quick way to check at the moment.
-                for (*parent_flow).each_child |child_flow: FlowContext| {
+                for child_flow in (*parent_flow).children() {
                     match child_flow {
                         InlineFlow(*) | InlineBlockFlow(*) => {
                             let mut scanner = TextRunScanner::new();
diff --git a/src/components/main/layout/float.rs b/src/components/main/layout/float.rs
index 2a2758d4aab..6f8107bb46e 100644
--- a/src/components/main/layout/float.rs
+++ b/src/components/main/layout/float.rs
@@ -15,7 +15,7 @@ use geom::rect::Rect;
 use gfx::display_list::DisplayList;
 use gfx::geometry::Au;
 use gfx::geometry;
-use servo_util::tree::{TreeNodeRef, TreeUtils};
+use servo_util::tree::TreeNodeRef;
 
 pub struct FloatFlowData {
     /// Data common to all flows.
@@ -55,7 +55,7 @@ impl FloatFlowData {
 
     pub fn teardown(&mut self) {
         self.common.teardown();
-        for self.box.iter().advance |box| {
+        for box in self.box.iter() {
             box.teardown();
         }
         self.box = None;
@@ -69,7 +69,7 @@ impl FloatFlowData {
         let mut pref_width = Au(0);
         let mut num_floats = 0;
 
-        for FloatFlow(self).each_child |child_ctx| {
+        for child_ctx in FloatFlow(self).children() {
             //assert!(child_ctx.starts_block_flow() || child_ctx.starts_inline_flow());
 
             do child_ctx.with_mut_base |child_node| {
@@ -108,7 +108,7 @@ impl FloatFlowData {
         // Parent usually sets this, but floats are never inorder
         self.common.is_inorder = false;
 
-        for self.box.iter().advance |&box| {
+        for &box in self.box.iter() {
             let style = box.style();
             do box.with_model |model| {
                 // Can compute padding here since we know containing block width.
@@ -162,7 +162,7 @@ impl FloatFlowData {
         self.common.position.size.width = remaining_width;
 
         let has_inorder_children = self.common.num_floats > 0;
-        for FloatFlow(self).each_child |kid| {
+        for kid in FloatFlow(self).children() {
             //assert!(kid.starts_block_flow() || kid.starts_inline_flow());
 
             do kid.with_mut_base |child_node| {
@@ -199,15 +199,13 @@ impl FloatFlowData {
             };
 
             do box.with_base |base| {
+                let noncontent_width = base.model.padding.left + base.model.padding.right +
+                    base.model.border.left + base.model.border.right;
+                let noncontent_height = base.model.padding.top + base.model.padding.bottom +
+                    base.model.border.top + base.model.border.bottom;
 
-            let noncontent_width = base.model.padding.left + base.model.padding.right +
-                base.model.border.left + base.model.border.right;
-            let noncontent_height = base.model.padding.top + base.model.padding.bottom +
-                base.model.border.top + base.model.border.bottom;
-
-            full_noncontent_width = noncontent_width + base.model.margin.left + base.model.margin.right;
-            full_noncontent_height = noncontent_height + base.model.margin.top + base.model.margin.bottom;
-
+                full_noncontent_width = noncontent_width + base.model.margin.left + base.model.margin.right;
+                full_noncontent_height = noncontent_height + base.model.margin.top + base.model.margin.bottom;
             }
 
         });
@@ -231,7 +229,7 @@ impl FloatFlowData {
         let has_inorder_children = self.common.num_floats > 0;
         if has_inorder_children {
             let mut float_ctx = FloatContext::new(self.floated_children);
-            for FloatFlow(self).each_child |kid| {
+            for kid in FloatFlow(self).children() {
                 do kid.with_mut_base |child_node| {
                     child_node.floats_in = float_ctx.clone();
                 }
@@ -245,14 +243,14 @@ impl FloatFlowData {
         let mut cur_y = Au(0);
         let mut top_offset = Au(0);
 
-        for self.box.iter().advance |&box| {
+        for &box in self.box.iter() {
             do box.with_model |model| {
                 top_offset = model.margin.top + model.border.top + model.padding.top;
                 cur_y = cur_y + top_offset;
             }
         }
 
-        for FloatFlow(self).each_child |kid| {
+        for kid in FloatFlow(self).children() {
             do kid.with_mut_base |child_node| {
                 child_node.position.origin.y = cur_y;
                 cur_y = cur_y + child_node.position.size.height;
@@ -279,7 +277,7 @@ impl FloatFlowData {
 
         
         //TODO(eatkinson): compute heights properly using the 'height' property.
-        for self.box.iter().advance |&box| {
+        for &box in self.box.iter() {
             let height_prop = 
                 MaybeAuto::from_height(box.style().height(),
                                        Au(0),
@@ -316,7 +314,7 @@ impl FloatFlowData {
 
         // go deeper into the flow tree
         let flow = FloatFlow(self);
-        for flow.each_child |child| {
+        for child in flow.children() {
             do child.with_mut_base |base| {
                 base.abs_position = offset + base.position.origin;
             }
diff --git a/src/components/main/layout/float_context.rs b/src/components/main/layout/float_context.rs
index 5528d5ae8f7..3c4bf3773ad 100644
--- a/src/components/main/layout/float_context.rs
+++ b/src/components/main/layout/float_context.rs
@@ -10,6 +10,7 @@ use std::util::replace;
 use std::vec;
 use std::i32::max_value;
 
+#[deriving(Clone)]
 pub enum FloatType{
     FloatLeft,
     FloatRight
@@ -28,6 +29,7 @@ struct FloatContextBase{
     offset: Point2D<Au>
 }
 
+#[deriving(Clone)]
 struct FloatData{
     bounds: Rect<Au>,
     f_type: FloatType
@@ -174,7 +176,7 @@ impl FloatContextBase{
         let mut r_bottom = None;
 
         // Find the float collisions for the given vertical range.
-        for self.float_data.iter().advance |float| {
+        for float in self.float_data.iter() {
             debug!("available_rect: Checking for collision against float");
             match *float{
                 None => (),
@@ -268,7 +270,7 @@ impl FloatContextBase{
 
     /// Returns true if the given rect overlaps with any floats.
     fn collides_with_float(&self, bounds: &Rect<Au>) -> bool {
-        for self.float_data.iter().advance |float| {
+        for float in self.float_data.iter() {
             match *float{
                 None => (),
                 Some(data) => {
@@ -290,7 +292,7 @@ impl FloatContextBase{
         let left = left - self.offset.x;
         let mut max_height = None;
 
-        for self.float_data.iter().advance |float| {
+        for float in self.float_data.iter() {
             match *float {
                 None => (),
                 Some(f_data) => {
@@ -298,7 +300,7 @@ impl FloatContextBase{
                        f_data.bounds.origin.x + f_data.bounds.size.width > left &&
                        f_data.bounds.origin.x < left + width {
                            let new_y = f_data.bounds.origin.y;
-                           max_height = Some(min(max_height.get_or_default(new_y), new_y));
+                           max_height = Some(min(max_height.unwrap_or_default(new_y), new_y));
                        }
                 }
             }
@@ -338,7 +340,7 @@ impl FloatContextBase{
                         let height = self.max_height_for_bounds(rect.origin.x, 
                                                                 rect.origin.y, 
                                                                 rect.size.width);
-                        let height = height.get_or_default(Au(max_value));
+                        let height = height.unwrap_or_default(Au(max_value));
                         return match info.f_type {
                             FloatLeft => Rect(Point2D(rect.origin.x, float_y),
                                               Size2D(rect.size.width, height)),
@@ -359,7 +361,7 @@ impl FloatContextBase{
 
     fn clearance(&self, clear: ClearType) -> Au {
         let mut clearance = Au(0);
-        for self.float_data.iter().advance |float| {
+        for float in self.float_data.iter() {
             match *float {
                 None => (),
                 Some(f_data) => {
diff --git a/src/components/main/layout/flow.rs b/src/components/main/layout/flow.rs
index 2d7db5d4a3c..83edbfa61ba 100644
--- a/src/components/main/layout/flow.rs
+++ b/src/components/main/layout/flow.rs
@@ -36,14 +36,13 @@ use layout::incremental::RestyleDamage;
 use css::node_style::StyledNode;
 
 use std::cell::Cell;
-use std::uint;
 use std::io::stderr;
 use geom::point::Point2D;
 use geom::rect::Rect;
 use gfx::display_list::DisplayList;
 use gfx::geometry::Au;
 use script::dom::node::{AbstractNode, LayoutView};
-use servo_util::tree::{TreeNode, TreeNodeRef, TreeUtils};
+use servo_util::tree::{TreeNode, TreeNodeRef};
 
 /// The type of the formatting context and data specific to each context, such as line box
 /// structures or float lists.
@@ -84,29 +83,25 @@ impl FlowContext {
     //
     // FIXME: Unify this with traverse_preorder_prune, which takes a separate
     // 'prune' function.
-    fn partially_traverse_preorder(&self, callback: &fn(FlowContext) -> bool) {
+    pub fn partially_traverse_preorder(&self, callback: &fn(FlowContext) -> bool) {
         if !callback((*self).clone()) {
             return;
         }
 
-        for self.each_child |kid| {
+        for kid in self.children() {
             // FIXME: Work around rust#2202. We should be able to pass the callback directly.
             kid.partially_traverse_preorder(|a| callback(a));
         }
     }
 
-    fn traverse_bu_sub_inorder (&self, callback: &fn(FlowContext) -> bool) -> bool {
-        for self.each_child |kid| {
+    pub fn traverse_bu_sub_inorder (&self, callback: &fn(FlowContext)) {
+        for kid in self.children() {
             // FIXME: Work around rust#2202. We should be able to pass the callback directly.
-            if !kid.traverse_bu_sub_inorder(|a| callback(a)) {
-                return false;
-            }
+            kid.traverse_bu_sub_inorder(|a| callback(a));
         }
 
         if !self.is_inorder() {
             callback((*self).clone())
-        } else {
-            true
         }
     }
 }
@@ -119,14 +114,14 @@ impl FlowData {
         // or we risk dynamic borrow failures.
         self.parent = None;
 
-        for self.first_child.iter().advance |flow| {
+        for flow in self.first_child.iter() {
             flow.teardown();
         }
         self.first_child = None;
 
         self.last_child = None;
 
-        for self.next_sibling.iter().advance |flow| {
+        for flow in self.next_sibling.iter() {
             flow.teardown();
         }
         self.next_sibling = None;
@@ -164,8 +159,50 @@ impl TreeNodeRef<FlowData> for FlowContext {
             TableFlow(info) => callback(info),
         }
     }
+
+    fn parent_node(node: &FlowData) -> Option<FlowContext> {
+        node.parent
+    }
+
+    fn first_child(node: &FlowData) -> Option<FlowContext> {
+        node.first_child
+    }
+
+    fn last_child(node: &FlowData) -> Option<FlowContext> {
+        node.last_child
+    }
+
+    fn prev_sibling(node: &FlowData) -> Option<FlowContext> {
+        node.prev_sibling
+    }
+
+    fn next_sibling(node: &FlowData) -> Option<FlowContext> {
+        node.next_sibling
+    }
+
+    fn set_parent_node(node: &mut FlowData, new_parent_node: Option<FlowContext>) {
+        node.parent = new_parent_node
+    }
+
+    fn set_first_child(node: &mut FlowData, new_first_child: Option<FlowContext>) {
+        node.first_child = new_first_child
+    }
+
+    fn set_last_child(node: &mut FlowData, new_last_child: Option<FlowContext>) {
+        node.last_child = new_last_child
+    }
+
+    fn set_prev_sibling(node: &mut FlowData, new_prev_sibling: Option<FlowContext>) {
+        node.prev_sibling = new_prev_sibling
+    }
+
+    fn set_next_sibling(node: &mut FlowData, new_next_sibling: Option<FlowContext>) {
+        node.next_sibling = new_next_sibling
+    }
 }
 
+impl TreeNode<FlowContext> for FlowData { }
+
 /// Data common to all flows.
 ///
 /// FIXME: We need a naming convention for pseudo-inheritance like this. How about
@@ -196,45 +233,20 @@ pub struct FlowData {
     is_inorder: bool,
 }
 
-impl TreeNode<FlowContext> for FlowData {
-    fn parent_node(&self) -> Option<FlowContext> {
-        self.parent
-    }
+pub struct BoxIterator {
+    priv boxes: ~[RenderBox],
+    priv index: uint,
+}
 
-    fn first_child(&self) -> Option<FlowContext> {
-        self.first_child
-    }
-
-    fn last_child(&self) -> Option<FlowContext> {
-        self.last_child
-    }
-
-    fn prev_sibling(&self) -> Option<FlowContext> {
-        self.prev_sibling
-    }
-
-    fn next_sibling(&self) -> Option<FlowContext> {
-        self.next_sibling
-    }
-
-    fn set_parent_node(&mut self, new_parent_node: Option<FlowContext>) {
-        self.parent = new_parent_node
-    }
-
-    fn set_first_child(&mut self, new_first_child: Option<FlowContext>) {
-        self.first_child = new_first_child
-    }
-
-    fn set_last_child(&mut self, new_last_child: Option<FlowContext>) {
-        self.last_child = new_last_child
-    }
-
-    fn set_prev_sibling(&mut self, new_prev_sibling: Option<FlowContext>) {
-        self.prev_sibling = new_prev_sibling
-    }
-
-    fn set_next_sibling(&mut self, new_next_sibling: Option<FlowContext>) {
-        self.next_sibling = new_next_sibling
+impl Iterator<RenderBox> for BoxIterator {
+    fn next(&mut self) -> Option<RenderBox> {
+        if self.index >= self.boxes.len() {
+            None
+        } else {
+            let v = self.boxes[self.index].clone();
+            self.index += 1;
+            Some(v)
+        }
     }
 }
 
@@ -408,43 +420,15 @@ impl<'self> FlowContext {
         }
     }
 
-    pub fn iter_all_boxes(&self, cb: &fn(RenderBox) -> bool) -> bool {
-        match *self {
-            BlockFlow(block) => {
-                let block = &mut *block;
-                for block.box.iter().advance |box| {
-                    if !cb(*box) {
-                        break;
-                    }
-                }
-            }
-            InlineFlow(inline) => {
-                let inline = &mut *inline;
-                for inline.boxes.iter().advance |box| {
-                    if !cb(*box) {
-                        break;
-                    }
-                }
-            }
-            _ => fail!(fmt!("Don't know how to iterate node's RenderBoxes for %?", self))
+    pub fn iter_all_boxes(&self) -> BoxIterator {
+        BoxIterator {
+            boxes: match *self {
+                BlockFlow (block)  => block.box.map_default(~[], |&x| ~[x]),
+                InlineFlow(inline) => inline.boxes.clone(),
+                _ => fail!(fmt!("Don't know how to iterate node's RenderBoxes for %?", self))
+            },
+            index: 0,
         }
-
-        true
-    }
-
-    pub fn iter_boxes_for_node(&self,
-                               node: AbstractNode<LayoutView>,
-                               callback: &fn(RenderBox) -> bool)
-                               -> bool {
-        for self.iter_all_boxes |box| {
-            if box.node() == node {
-                if !callback(box) {
-                    break;
-                }
-            }
-        }
-
-        true
     }
 
     /// Dumps the flow tree for debugging.
@@ -455,7 +439,7 @@ impl<'self> FlowContext {
     /// Dumps the flow tree, for debugging, with indentation.
     pub fn dump_indent(&self, indent: uint) {
         let mut s = ~"|";
-        for uint::range(0, indent) |_i| {
+        for _ in range(0, indent) {
             s.push_str("---- ");
         }
 
@@ -463,7 +447,7 @@ impl<'self> FlowContext {
         stderr().write_line(s);
 
         // FIXME: this should have a pure/const version?
-        for self.each_child |child| {
+        for child in self.children() {
             child.dump_indent(indent + 1)
         }
     }
diff --git a/src/components/main/layout/inline.rs b/src/components/main/layout/inline.rs
index 3886695c4d3..d1a9c5e9708 100644
--- a/src/components/main/layout/inline.rs
+++ b/src/components/main/layout/inline.rs
@@ -21,8 +21,9 @@ use newcss::values::{CSSTextAlignLeft, CSSTextAlignCenter, CSSTextAlignRight, CS
 use newcss::units::{Em, Px, Pt};
 use newcss::values::{CSSLineHeightNormal, CSSLineHeightNumber, CSSLineHeightLength, CSSLineHeightPercentage};
 use servo_util::range::Range;
-use servo_util::tree::{TreeNodeRef, TreeUtils};
-use extra::deque::Deque;
+use servo_util::tree::TreeNodeRef;
+use extra::container::Deque;
+use extra::ringbuf::RingBuf;
 
 /*
 Lineboxes are represented as offsets into the child list, rather than
@@ -62,7 +63,7 @@ struct LineboxScanner {
     flow: FlowContext,
     floats: FloatContext,
     new_boxes: ~[RenderBox],
-    work_list: @mut Deque<RenderBox>,
+    work_list: @mut RingBuf<RenderBox>,
     pending_line: LineBox,
     lines: ~[LineBox],
     cur_y: Au,
@@ -76,7 +77,7 @@ impl LineboxScanner {
             flow: inline,
             floats: float_ctx,
             new_boxes: ~[],
-            work_list: @mut Deque::new(),
+            work_list: @mut RingBuf::new(),
             pending_line: LineBox {
                 range: Range::empty(), 
                 bounds: Rect(Point2D(Au(0), Au(0)), Size2D(Au(0), Au(0))), 
@@ -122,7 +123,7 @@ impl LineboxScanner {
                     debug!("LineboxScanner: Working with box from box list: b%d", box.id());
                     box
                 } else {
-                    let box = self.work_list.pop_front();
+                    let box = self.work_list.pop_front().unwrap();
                     debug!("LineboxScanner: Working with box from work list: b%d", box.id());
                     box
                 };
@@ -176,7 +177,7 @@ impl LineboxScanner {
         match box {
             ImageRenderBoxClass(image_box) => {
                 let size = image_box.image.get_size();
-                let height = Au::from_px(size.get_or_default(Size2D(0, 0)).height);
+                let height = Au::from_px(size.unwrap_or_default(Size2D(0, 0)).height);
                 image_box.base.position.size.height = height;
                 debug!("box_height: found image height: %?", height);
                 height
@@ -360,11 +361,11 @@ impl LineboxScanner {
                 self.pending_line.green_zone = next_green_zone;
 
                 assert!(!line_is_empty, "Non-terminating line breaking");
-                self.work_list.add_front(in_box);
+                self.work_list.push_front(in_box);
                 return true;
             } else {
                 debug!("LineboxScanner: case=adding box collides vertically with floats: breaking line");
-                self.work_list.add_front(in_box);
+                self.work_list.push_front(in_box);
                 return false;
             }
         }
@@ -407,7 +408,7 @@ impl LineboxScanner {
                     match (left, right) {
                         (Some(left_box), Some(right_box)) => {
                             self.push_box_to_line(left_box);
-                            self.work_list.add_front(right_box);
+                            self.work_list.push_front(right_box);
                         }
                         (Some(left_box), None) => self.push_box_to_line(left_box),
                         (None, Some(right_box)) => self.push_box_to_line(right_box),
@@ -423,7 +424,7 @@ impl LineboxScanner {
                         match (left, right) {
                             (Some(left_box), Some(right_box)) => {
                                 self.push_box_to_line(left_box);
-                                self.work_list.add_front(right_box);
+                                self.work_list.push_front(right_box);
                             }
                             (Some(left_box), None) => {
                                 self.push_box_to_line(left_box);
@@ -438,7 +439,7 @@ impl LineboxScanner {
                         return true;
                     } else {
                         debug!("LineboxScanner: case=split box didn't fit, not appending and deferring original box.");
-                        self.work_list.add_front(in_box);
+                        self.work_list.push_front(in_box);
                         return false;
                     }
                 }
@@ -491,7 +492,7 @@ impl InlineFlowData {
 
     pub fn teardown(&mut self) {
         self.common.teardown();
-        for self.boxes.iter().advance |box| {
+        for box in self.boxes.iter() {
             box.teardown();
         }
         self.boxes = ~[];
@@ -515,7 +516,7 @@ impl InlineFlowData {
     pub fn bubble_widths_inline(@mut self, ctx: &mut LayoutContext) {
         let mut num_floats = 0;
 
-        for InlineFlow(self).each_child |kid| {
+        for kid in InlineFlow(self).children() {
             do kid.with_mut_base |base| {
                 num_floats += base.num_floats;
                 base.floats_in = FloatContext::new(base.num_floats);
@@ -528,7 +529,7 @@ impl InlineFlowData {
             let mut min_width = Au(0);
             let mut pref_width = Au(0);
 
-            for this.boxes.iter().advance |box| {
+            for box in this.boxes.iter() {
                 debug!("FlowContext[%d]: measuring %s", self.common.id, box.debug_str());
                 min_width = Au::max(min_width, box.get_min_width(ctx));
                 pref_width = Au::max(pref_width, box.get_pref_width(ctx));
@@ -549,11 +550,11 @@ impl InlineFlowData {
         // `RenderBox`.
         {
             let this = &mut *self;
-            for this.boxes.iter().advance |&box| {
+            for &box in this.boxes.iter() {
                 match box {
                     ImageRenderBoxClass(image_box) => {
                         let size = image_box.image.get_size();
-                        let width = Au::from_px(size.get_or_default(Size2D(0, 0)).width);
+                        let width = Au::from_px(size.unwrap_or_default(Size2D(0, 0)).width);
                         image_box.base.position.size.width = width;
                     }
                     TextRenderBoxClass(_) => {
@@ -571,7 +572,7 @@ impl InlineFlowData {
             } // End of for loop.
         }
 
-        for InlineFlow(self).each_child |kid| {
+        for kid in InlineFlow(self).children() {
             do kid.with_mut_base |base| {
                 base.position.size.width = self.common.position.size.width;
                 base.is_inorder = self.common.is_inorder;
@@ -587,7 +588,7 @@ impl InlineFlowData {
     }
 
     pub fn assign_height_inorder_inline(@mut self, ctx: &mut LayoutContext) {
-        for InlineFlow(self).each_child |kid| {
+        for kid in InlineFlow(self).children() {
             kid.assign_height_inorder(ctx);
         }
         self.assign_height_inline(ctx);
@@ -607,7 +608,7 @@ impl InlineFlowData {
         scanner.scan_for_lines();
 
         // Now, go through each line and lay out the boxes inside
-        for self.lines.iter().advance |line| {
+        for line in self.lines.iter() {
             // We need to distribute extra width based on text-align.
             let mut slack_width = line.green_zone.width - line.bounds.size.width;
             if slack_width < Au(0) {
@@ -633,7 +634,7 @@ impl InlineFlowData {
                 // So sorry, but justified text is more complicated than shuffling linebox coordinates.
                 // TODO(Issue #213): implement `text-align: justify`
                 CSSTextAlignLeft | CSSTextAlignJustify => {
-                    for line.range.eachi |i| {
+                    for i in line.range.eachi() {
                         do self.boxes[i].with_mut_base |base| {
                             base.position.origin.x = offset_x;
                             offset_x = offset_x + base.position.size.width;
@@ -642,7 +643,7 @@ impl InlineFlowData {
                 }
                 CSSTextAlignCenter => {
                     offset_x = offset_x + slack_width.scale_by(0.5f);
-                    for line.range.eachi |i| {
+                    for i in line.range.eachi() {
                         do self.boxes[i].with_mut_base |base| {
                             base.position.origin.x = offset_x;
                             offset_x = offset_x + base.position.size.width;
@@ -651,7 +652,7 @@ impl InlineFlowData {
                 }
                 CSSTextAlignRight => {
                     offset_x = offset_x + slack_width;
-                    for line.range.eachi |i| {
+                    for i in line.range.eachi() {
                         do self.boxes[i].with_mut_base |base| {
                             base.position.origin.x = offset_x;
                             offset_x = offset_x + base.position.size.width;
@@ -665,13 +666,13 @@ impl InlineFlowData {
             // the baseline.
             let mut baseline_offset = Au(0);
             let mut max_height = Au(0);
-            for line.range.eachi |box_i| {
+            for box_i in line.range.eachi() {
                 let cur_box = self.boxes[box_i];
 
                 match cur_box {
                     ImageRenderBoxClass(image_box) => {
                         let size = image_box.image.get_size();
-                        let height = Au::from_px(size.get_or_default(Size2D(0, 0)).height);
+                        let height = Au::from_px(size.unwrap_or_default(Size2D(0, 0)).height);
                         image_box.base.position.size.height = height;
 
                         image_box.base.position.translate(&Point2D(Au(0), -height))
@@ -718,7 +719,7 @@ impl InlineFlowData {
             }
 
             // Now go back and adjust the Y coordinates to match the baseline we determined.
-            for line.range.eachi |box_i| {
+            for box_i in line.range.eachi() {
                 let cur_box = self.boxes[box_i];
 
                 // TODO(#226): This is completely wrong. We need to use the element's `line-height`
@@ -765,7 +766,7 @@ impl InlineFlowData {
                self.common.id,
                self.boxes.len());
 
-        for self.boxes.iter().advance |box| {
+        for box in self.boxes.iter() {
             box.build_display_list(builder, dirty, &self.common.abs_position, list)
         }
 
diff --git a/src/components/main/layout/layout_task.rs b/src/components/main/layout/layout_task.rs
index 5170d6f5f88..a3e7901c3c0 100644
--- a/src/components/main/layout/layout_task.rs
+++ b/src/components/main/layout/layout_task.rs
@@ -41,10 +41,10 @@ use script::script_task::{ReflowCompleteMsg, ScriptChan, SendEventMsg};
 use servo_msg::constellation_msg::{ConstellationChan, PipelineId};
 use servo_net::image_cache_task::{ImageCacheTask, ImageResponseMsg};
 use servo_net::local_image_cache::LocalImageCache;
-use servo_util::tree::{TreeNodeRef, TreeUtils};
+use servo_util::tree::TreeNodeRef;
 use servo_util::time::{ProfilerChan, profile};
 use servo_util::time;
-use extra::net::url::Url;
+use extra::url::Url;
 
 struct LayoutTask {
     id: PipelineId,
@@ -181,7 +181,7 @@ impl LayoutTask {
         };
 
         // FIXME: Bad copy!
-        let doc_url = copy data.url;
+        let doc_url = data.url.clone();
         let script_chan = data.script_chan.clone();
 
         debug!("layout: received layout request for: %s", doc_url.to_str());
@@ -232,7 +232,7 @@ impl LayoutTask {
 
         // Propagate restyle damage up and down the tree, as appropriate.
         // FIXME: Merge this with flow tree building and/or the other traversals.
-        for layout_root.traverse_preorder |flow| {
+        for flow in layout_root.traverse_preorder() {
             // Also set any damage implied by resize.
             if resized {
                 do flow.with_mut_base |base| {
@@ -242,7 +242,7 @@ impl LayoutTask {
 
             let prop = flow.with_base(|base| base.restyle_damage.propagate_down());
             if prop.is_nonempty() {
-                for flow.each_child |kid_ctx| {
+                for kid_ctx in flow.children() {
                     do kid_ctx.with_mut_base |kid| {
                         kid.restyle_damage.union_in_place(prop);
                     }
@@ -250,8 +250,8 @@ impl LayoutTask {
             }
         }
 
-        for layout_root.traverse_postorder |flow| {
-            for flow.each_child |child| {
+        for flow in layout_root.traverse_postorder() {
+            for child in flow.children() {
                 do child.with_base |child_base| {
                     do flow.with_mut_base |base| {
                         base.restyle_damage.union_in_place(child_base.restyle_damage);
@@ -266,20 +266,20 @@ impl LayoutTask {
         // Perform the primary layout passes over the flow tree to compute the locations of all
         // the boxes.
         do profile(time::LayoutMainCategory, self.profiler_chan.clone()) {
-            for layout_root.traverse_postorder_prune(|f| f.restyle_damage().lacks(BubbleWidths)) |flow| {
+            for flow in layout_root.traverse_postorder_prune(|f| f.restyle_damage().lacks(BubbleWidths)) {
                 flow.bubble_widths(&mut layout_ctx);
             };
 
             // FIXME: We want to do
-            //     for layout_root.traverse_preorder_prune(|f| f.restyle_damage().lacks(Reflow)) |flow| {
+            //     for flow in layout_root.traverse_preorder_prune(|f| f.restyle_damage().lacks(Reflow)) {
             // but FloatContext values can't be reused, so we need to recompute them every time.
-            for layout_root.traverse_preorder |flow| {
+            for flow in layout_root.traverse_preorder() {
                 flow.assign_widths(&mut layout_ctx);
             };
 
             // For now, this is an inorder traversal
             // FIXME: prune this traversal as well
-            for layout_root.traverse_bu_sub_inorder |flow| {
+            do layout_root.traverse_bu_sub_inorder |flow| {
                 flow.assign_height(&mut layout_ctx);
             }
         }
@@ -366,8 +366,10 @@ impl LayoutTask {
                     None => Err(()),
                     Some(flow) => {
                         let mut boxes = ~[];
-                        for flow.iter_boxes_for_node(node) |box| {
-                            boxes.push(box.content_box());
+                        for box in flow.iter_all_boxes() {
+                            if box.node() == node {
+                                boxes.push(box.content_box());
+                            }
                         }
 
                         Ok(ContentBoxesResponse(boxes))
@@ -382,7 +384,7 @@ impl LayoutTask {
                     transmute(node)
                 };
                 let mut flow_node: AbstractNode<LayoutView> = node;
-                for node.traverse_preorder |node| {
+                for node in node.traverse_preorder() {
                     if node.layout_data().flow.is_some() {
                         flow_node = node;
                         break;
@@ -413,7 +415,7 @@ impl LayoutTask {
                         let mut resp = Err(());
                         let display_list = &display_list.take().list;
                         // iterate in reverse to ensure we have the most recently painted render box
-                        for display_list.rev_iter().advance |display_item| {
+                        for display_item in display_list.rev_iter() {
                             let bounds = display_item.bounds();
                             // TODO this check should really be performed by a method of DisplayItem
                             if x <= bounds.origin.x + bounds.size.width &&
diff --git a/src/components/main/layout/text.rs b/src/components/main/layout/text.rs
index cf9d8f49bcc..1e744a4f337 100644
--- a/src/components/main/layout/text.rs
+++ b/src/components/main/layout/text.rs
@@ -4,7 +4,6 @@
 
 //! Text layout.
 
-use std::uint;
 use std::vec;
 
 use gfx::text::text_run::TextRun;
@@ -13,7 +12,6 @@ use layout::box::{RenderBox, RenderBoxBase, TextRenderBox};
 use layout::box::{TextRenderBoxClass, UnscannedTextRenderBoxClass};
 use layout::context::LayoutContext;
 use layout::flow::FlowContext;
-use layout::util::{NodeRange};
 use newcss::values::{CSSTextDecoration, CSSTextDecorationUnderline};
 use servo_util::range::Range;
 
@@ -50,7 +48,7 @@ pub trait UnscannedMethods {
 impl UnscannedMethods for RenderBox {
     fn raw_text(&self) -> ~str {
         match *self {
-            UnscannedTextRenderBoxClass(text_box) => copy text_box.text,
+            UnscannedTextRenderBoxClass(text_box) => text_box.text.clone(),
             _ => fail!(~"unsupported operation: box.raw_text() on non-unscanned text box."),
         }
     }
@@ -75,7 +73,7 @@ impl TextRunScanner {
 
         let mut last_whitespace = true;
         let mut out_boxes = ~[];
-        for uint::range(0, flow.inline().boxes.len()) |box_i| {
+        for box_i in range(0, flow.inline().boxes.len()) {
             debug!("TextRunScanner: considering box: %?", flow.inline().boxes[box_i].debug_str());
             if box_i > 0 && !can_coalesce_text_nodes(flow.inline().boxes, box_i-1, box_i) {
                 last_whitespace = self.flush_clump_to_list(ctx, flow, last_whitespace, &mut out_boxes);
@@ -204,7 +202,7 @@ impl TextRunScanner {
                 let mut run_str: ~str = ~"";
                 let mut new_ranges: ~[Range] = ~[];
                 let mut char_total = 0;
-                for uint::range(0, transformed_strs.len()) |i| {
+                for i in range(0, transformed_strs.len()) {
                     let added_chars = transformed_strs[i].char_len();
                     new_ranges.push(Range::new(char_total, added_chars));
                     run_str.push_str(transformed_strs[i]);
@@ -231,7 +229,7 @@ impl TextRunScanner {
 
                 // Make new boxes with the run and adjusted text indices.
                 debug!("TextRunScanner: pushing box(es) in range: %?", self.clump);
-                for clump.eachi |i| {
+                for i in clump.eachi() {
                     let range = new_ranges[i - self.clump.begin()];
                     if range.length() == 0 {
                         debug!("Elided an `UnscannedTextbox` because it was zero-length after \
@@ -241,7 +239,7 @@ impl TextRunScanner {
                     }
 
                     do in_boxes[i].with_base |base| {
-                        let new_box = @mut adapt_textbox_with_range(*base, run.get(), range);
+                        let new_box = @mut adapt_textbox_with_range(*base, run.unwrap(), range);
                         out_boxes.push(TextRenderBoxClass(new_box));
                     }
                 }
@@ -249,19 +247,19 @@ impl TextRunScanner {
         } // End of match.
 
         debug!("--- In boxes: ---");
-        for in_boxes.iter().enumerate().advance |(i, box)| {
+        for (i, box) in in_boxes.iter().enumerate() {
             debug!("%u --> %s", i, box.debug_str());
         }
         debug!("------------------");
 
         debug!("--- Out boxes: ---");
-        for out_boxes.iter().enumerate().advance |(i, box)| {
+        for (i, box) in out_boxes.iter().enumerate() {
             debug!("%u --> %s", i, box.debug_str());
         }
         debug!("------------------");
 
         debug!("--- Elem ranges: ---");
-        for inline.elems.eachi_mut |i: uint, nr: &NodeRange| {
+        for (i, nr) in inline.elems.eachi() {
             debug!("%u: %? --> %s", i, nr.range, nr.node.debug_str()); ()
         }
         debug!("--------------------");
diff --git a/src/components/main/layout/util.rs b/src/components/main/layout/util.rs
index 00d4dae218c..e976e50c635 100644
--- a/src/components/main/layout/util.rs
+++ b/src/components/main/layout/util.rs
@@ -6,6 +6,9 @@ use layout::box::{RenderBox};
 use script::dom::node::{AbstractNode, LayoutView};
 use servo_util::range::Range;
 
+use std::iterator::Enumerate;
+use std::vec::VecIterator;
+
 pub struct NodeRange {
     node: AbstractNode<LayoutView>,
     range: Range,
@@ -13,7 +16,7 @@ pub struct NodeRange {
 
 impl NodeRange {
     pub fn new(node: AbstractNode<LayoutView>, range: &Range) -> NodeRange {
-        NodeRange { node: node, range: copy *range }
+        NodeRange { node: node, range: (*range).clone() }
     }
 }
 
@@ -31,7 +34,7 @@ impl ElementMapping {
     }
 
     pub fn each(&self, callback: &fn(nr: &NodeRange) -> bool) -> bool {
-        for self.entries.iter().advance |nr| {
+        for nr in self.entries.iter() {
             if !callback(nr) {
                 break
             }
@@ -39,41 +42,27 @@ impl ElementMapping {
         true
     }
 
-    pub fn eachi(&self, callback: &fn(i: uint, nr: &NodeRange) -> bool) -> bool {
-        for self.entries.iter().enumerate().advance |(i, nr)| {
-            if !callback(i, nr) {
-                break
-            }
-        }
-        true
-    }
-
-    pub fn eachi_mut(&self, callback: &fn(i: uint, nr: &NodeRange) -> bool) -> bool {
-        for self.entries.iter().enumerate().advance |(i, nr)| {
-            if !callback(i, nr) {
-                break
-            }
-        }
-        true
+    pub fn eachi<'a>(&'a self) -> Enumerate<VecIterator<'a, NodeRange>> {
+        self.entries.iter().enumerate()
     }
 
     pub fn repair_for_box_changes(&mut self, old_boxes: &[RenderBox], new_boxes: &[RenderBox]) {
         let entries = &mut self.entries;
 
         debug!("--- Old boxes: ---");
-        for old_boxes.iter().enumerate().advance |(i, box)| {
+        for (i, box) in old_boxes.iter().enumerate() {
             debug!("%u --> %s", i, box.debug_str());
         }
         debug!("------------------");
 
         debug!("--- New boxes: ---");
-        for new_boxes.iter().enumerate().advance |(i, box)| {
+        for (i, box) in new_boxes.iter().enumerate() {
             debug!("%u --> %s", i, box.debug_str());
         }
         debug!("------------------");
 
         debug!("--- Elem ranges before repair: ---");
-        for entries.iter().enumerate().advance |(i, nr)| {
+        for (i, nr) in entries.iter().enumerate() {
             debug!("%u: %? --> %s", i, nr.range, nr.node.debug_str());
         }
         debug!("----------------------------------");
@@ -126,7 +115,7 @@ impl ElementMapping {
                 }
             }
         debug!("--- Elem ranges after repair: ---");
-        for entries.iter().enumerate().advance |(i, nr)| {
+        for (i, nr) in entries.iter().enumerate() {
             debug!("%u: %? --> %s", i, nr.range, nr.node.debug_str());
         }
         debug!("----------------------------------");
diff --git a/src/components/main/pipeline.rs b/src/components/main/pipeline.rs
index 1ea7965b02a..ab12a1f73e0 100644
--- a/src/components/main/pipeline.rs
+++ b/src/components/main/pipeline.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use extra::net::url::Url;
+use extra::url::Url;
 use compositing::CompositorChan;
 use gfx::render_task::{RenderChan, RenderTask};
 use gfx::render_task::{PaintPermissionGranted, PaintPermissionRevoked};
@@ -52,7 +52,7 @@ impl Pipeline {
         RenderTask::create(id,
                            render_port,
                            compositor_chan.clone(),
-                           copy opts,
+                           opts.clone(),
                            profiler_chan.clone());
 
         LayoutTask::create(id,
@@ -61,7 +61,7 @@ impl Pipeline {
                            script_pipeline.script_chan.clone(),
                            render_chan.clone(),
                            image_cache_task.clone(),
-                           copy opts,
+                           opts.clone(),
                            profiler_chan);
 
         let new_layout_info = NewLayoutInfo {
@@ -109,7 +109,7 @@ impl Pipeline {
         RenderTask::create(id,
                            render_port,
                            compositor_chan.clone(),
-                           copy opts,
+                           opts.clone(),
                            profiler_chan.clone());
 
         LayoutTask::create(id,
@@ -118,7 +118,7 @@ impl Pipeline {
                            script_chan.clone(),
                            render_chan.clone(),
                            image_cache_task,
-                           copy opts,
+                           opts.clone(),
                            profiler_chan);
         Pipeline::new(id,
                       subpage_id,
diff --git a/src/components/main/platform/common/glfw_windowing.rs b/src/components/main/platform/common/glfw_windowing.rs
index 327d7423540..b589258f88c 100644
--- a/src/components/main/platform/common/glfw_windowing.rs
+++ b/src/components/main/platform/common/glfw_windowing.rs
@@ -25,7 +25,7 @@ static THROBBER: [char, ..8] = [ '⣾', '⣽', '⣻', '⢿', '⡿', '⣟', '⣯'
 pub struct Application;
 
 impl ApplicationMethods for Application {
-    pub fn new() -> Application {
+    fn new() -> Application {
         glfw::init();
         Application
     }
diff --git a/src/components/main/servo.rc b/src/components/main/servo.rc
index 826b04f6d12..bb16497fe65 100755
--- a/src/components/main/servo.rc
+++ b/src/components/main/servo.rc
@@ -16,7 +16,7 @@ extern mod azure;
 extern mod geom;
 extern mod gfx (name = "gfx");
 extern mod glfw;
-extern mod http_client;
+//extern mod http_client;
 extern mod js;
 extern mod layers;
 extern mod newcss (name = "css");
@@ -39,17 +39,21 @@ use compositing::{CompositorChan, CompositorTask};
 use constellation::Constellation;
 use servo_msg::constellation_msg::{ExitMsg, InitLoadUrlMsg};
 
+#[cfg(not(test))]
 use gfx::opts;
+
 use servo_net::image_cache_task::ImageCacheTask;
 use servo_net::resource_task::ResourceTask;
 use servo_util::time::{Profiler, ProfilerChan, PrintMsg};
-use extra::uv_global_loop;
 
 pub use gfx::opts::Opts;
 pub use gfx::text;
 pub use servo_util::url::make_url;
 use std::comm;
+#[cfg(not(test))]
 use std::os;
+use std::rt::rtio::RtioTimer;
+use std::rt::io::timer::Timer;
 
 #[path="compositing/mod.rs"]
 pub mod compositing;
@@ -57,8 +61,8 @@ pub mod compositing;
 pub mod macros;
 
 pub mod css {
-    priv mod select_handler;
-    priv mod node_util;
+    mod select_handler;
+    mod node_util;
 
     pub mod select;
     pub mod matching;
@@ -94,56 +98,75 @@ pub mod platform;
 #[path = "util/mod.rs"]
 pub mod util;
 
-fn main() {
-    run(&opts::from_cmdline_args(os::args()))
+#[cfg(not(test))]
+#[start]
+fn start(argc: int, argv: **u8, crate_map: *u8) -> int {
+    do std::rt::start_on_main_thread(argc, argv, crate_map) {
+        let opts = opts::from_cmdline_args(os::args());
+        run(opts)
+    }
 }
 
-fn run(opts: &Opts) {
+fn run(opts: Opts) {
     let (shutdown_port, shutdown_chan) = comm::stream();
-
-    // Create the profiler channel.
     let (profiler_port, profiler_chan) = comm::stream();
+    let (compositor_port, compositor_chan) = comm::stream();
+
     let profiler_chan = ProfilerChan::new(profiler_chan);
     Profiler::create(profiler_port);
-    do opts.profiler_period.map |period| {
+    do opts.profiler_period.map |&period| {
         let profiler_chan = profiler_chan.clone();
-        let period = *period;
+        let period = (period * 1000f) as u64;
         do spawn {
+            let tm = Timer::new().unwrap();
             loop {
-                extra::timer::sleep(&uv_global_loop::get(),
-                                  (period * 1000f) as uint);
+                tm.sleep(period);
                 profiler_chan.send(PrintMsg);
             }
         }
     };
-
-    // Create the compositor.
-    let (compositor_port, compositor_chan) = comm::stream();
     let compositor_chan = CompositorChan::new(compositor_chan);
-    CompositorTask::create(opts.clone(), compositor_port, profiler_chan.clone(), shutdown_chan);
+    let profiler_chan_clone = profiler_chan.clone();
 
-    // Create a Servo instance.
+    let opts_clone = opts.clone();
 
-    let resource_task = ResourceTask();
-    let image_cache_task = ImageCacheTask(resource_task.clone());
-    let constellation_chan = Constellation::start(compositor_chan.clone(),
-                                    opts,
-                                    resource_task,
-                                    image_cache_task,
-                                    profiler_chan.clone());
+    do spawn {
+        let profiler_chan = profiler_chan_clone.clone();
+        let compositor_chan = compositor_chan.clone();
 
-    // Send the URL command to the constellation.
-    for opts.urls.iter().advance |filename| {
-        constellation_chan.send(InitLoadUrlMsg(make_url(filename.clone(), None)))
+        let opts = &opts_clone.clone();
+
+        // Create a Servo instance.
+
+        let resource_task = ResourceTask();
+        let image_cache_task = ImageCacheTask(resource_task.clone());
+        let constellation_chan = Constellation::start(compositor_chan.clone(),
+                                                      opts,
+                                                      resource_task,
+                                                      image_cache_task,
+                                                      profiler_chan.clone());
+
+        // Send the URL command to the constellation.
+        for filename in opts.urls.iter() {
+            constellation_chan.send(InitLoadUrlMsg(make_url(filename.clone(), None)))
+        }
+
+        // Wait for the compositor to shut down.
+        shutdown_port.recv();
+
+        // Shut the constellation down.
+        debug!("master: Shut down");
+        let (exit_response_from_constellation, exit_chan) = comm::stream();
+        constellation_chan.send(ExitMsg(exit_chan));
+        exit_response_from_constellation.recv();
     }
 
-    // Wait for the compositor to shut down.
-    shutdown_port.recv();
 
-    // Shut the constellation down.
-    debug!("master: Shut down");
-    let (exit_response_from_constellation, exit_chan) = comm::stream();
-    constellation_chan.send(ExitMsg(exit_chan));
-    exit_response_from_constellation.recv();
+    let compositor_task = CompositorTask::new(opts,
+                                              compositor_port,
+                                              profiler_chan,
+                                              shutdown_chan);
+    debug!("preparing to enter main loop");
+    compositor_task.run();
 }
 
diff --git a/src/components/main/windowing.rs b/src/components/main/windowing.rs
index f4fbca5d58c..dcf94615831 100644
--- a/src/components/main/windowing.rs
+++ b/src/components/main/windowing.rs
@@ -51,21 +51,21 @@ pub trait ApplicationMethods {
 
 pub trait WindowMethods<A> {
     /// Creates a new window.
-    pub fn new(app: &A) -> @mut Self;
+    fn new(app: &A) -> @mut Self;
     /// Returns the size of the window.
-    pub fn size(&self) -> Size2D<f32>;
+    fn size(&self) -> Size2D<f32>;
     /// Presents the window to the screen (perhaps by page flipping).
-    pub fn present(&mut self);
+    fn present(&mut self);
  
     /// Spins the event loop and returns the next event.
-    pub fn recv(@mut self) -> WindowEvent;
+    fn recv(@mut self) -> WindowEvent;
 
     /// Sets the ready state of the current page.
-    pub fn set_ready_state(@mut self, ready_state: ReadyState);
+    fn set_ready_state(@mut self, ready_state: ReadyState);
     /// Sets the render state of the current page.
-    pub fn set_render_state(@mut self, render_state: RenderState);
+    fn set_render_state(@mut self, render_state: RenderState);
 
     /// Returns the hidpi factor of the monitor.
-    pub fn hidpi_factor(@mut self) -> f32;
+    fn hidpi_factor(@mut self) -> f32;
 }
 
diff --git a/src/components/msg/compositor_msg.rs b/src/components/msg/compositor_msg.rs
index 80f0c0703d3..410da56f6e0 100644
--- a/src/components/msg/compositor_msg.rs
+++ b/src/components/msg/compositor_msg.rs
@@ -61,7 +61,7 @@ pub trait RenderListener {
     fn new_layer(&self, PipelineId, Size2D<uint>);
     fn resize_layer(&self, PipelineId, Size2D<uint>);
     fn delete_layer(&self, PipelineId);
-    fn paint(&self, id: PipelineId, layer_buffer_set: arc::ARC<LayerBufferSet>);
+    fn paint(&self, id: PipelineId, layer_buffer_set: arc::Arc<LayerBufferSet>);
     fn set_render_state(&self, render_state: RenderState);
 }
 
diff --git a/src/components/msg/constellation_msg.rs b/src/components/msg/constellation_msg.rs
index 419aadf1ae3..af0a01184a3 100644
--- a/src/components/msg/constellation_msg.rs
+++ b/src/components/msg/constellation_msg.rs
@@ -6,7 +6,7 @@
 /// coupling between these two components
 
 use std::comm::{Chan, SharedChan};
-use extra::net::url::Url;
+use extra::url::Url;
 use extra::future::Future;
 use geom::size::Size2D;
 
diff --git a/src/components/net/image/holder.rs b/src/components/net/image/holder.rs
index bf56b6413e3..096c07b2f19 100644
--- a/src/components/net/image/holder.rs
+++ b/src/components/net/image/holder.rs
@@ -8,18 +8,18 @@ use local_image_cache::LocalImageCache;
 
 use std::util::replace;
 use geom::size::Size2D;
-use extra::net::url::Url;
-use extra::arc::ARC;
+use extra::url::Url;
+use extra::arc::Arc;
 
 // FIXME: Nasty coupling here This will be a problem if we want to factor out image handling from
 // the network stack. This should probably be factored out into an interface and use dependency
 // injection.
 
 /// A struct to store image data. The image will be loaded once the first time it is requested,
-/// and an ARC will be stored.  Clones of this ARC are given out on demand.
+/// and an Arc will be stored.  Clones of this Arc are given out on demand.
 pub struct ImageHolder {
     url: Url,
-    image: Option<ARC<~Image>>,
+    image: Option<Arc<~Image>>,
     cached_size: Size2D<int>,
     local_image_cache: @mut LocalImageCache,
 }
@@ -65,7 +65,7 @@ impl ImageHolder {
         }
     }
 
-    pub fn get_image(&mut self) -> Option<ARC<~Image>> {
+    pub fn get_image(&mut self) -> Option<Arc<~Image>> {
         debug!("get_image() %?", self.url);
 
         // If this is the first time we've called this function, load
diff --git a/src/components/net/image_cache_task.rs b/src/components/net/image_cache_task.rs
index aa0440ff701..a6f3dfb529f 100644
--- a/src/components/net/image_cache_task.rs
+++ b/src/components/net/image_cache_task.rs
@@ -13,8 +13,8 @@ use std::task::spawn;
 use std::to_str::ToStr;
 use std::util::replace;
 use std::result;
-use extra::arc::ARC;
-use extra::net::url::Url;
+use extra::arc::Arc;
+use extra::url::Url;
 
 pub enum Msg {
     /// Tell the cache that we may need a particular image soon. Must be posted
@@ -29,7 +29,7 @@ pub enum Msg {
     Decode(Url),
 
     /// Used by the decoder tasks to post decoded images back to the cache
-    priv StoreImage(Url, Option<ARC<~Image>>),
+    priv StoreImage(Url, Option<Arc<~Image>>),
 
     /// Request an Image object for a URL. If the image is not is not immediately
     /// available then ImageNotReady is returned.
@@ -46,7 +46,7 @@ pub enum Msg {
 }
 
 pub enum ImageResponseMsg {
-    ImageReady(ARC<~Image>),
+    ImageReady(Arc<~Image>),
     ImageNotReady,
     ImageFailed
 }
@@ -157,21 +157,22 @@ struct ImageCache {
     need_exit: Option<Chan<()>>,
 }
 
+#[deriving(Clone)]
 enum ImageState {
     Init,
     Prefetching(AfterPrefetch),
     Prefetched(@Cell<~[u8]>),
     Decoding,
-    Decoded(@ARC<~Image>),
+    Decoded(@Arc<~Image>),
     Failed
 }
 
+#[deriving(Clone)]
 enum AfterPrefetch {
     DoDecode,
     DoNotDecode
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 impl ImageCache {
     pub fn run(&mut self) {
         let mut msg_handlers: ~[~fn(msg: &Msg)] = ~[];
@@ -179,7 +180,7 @@ impl ImageCache {
         loop {
             let msg = self.port.recv();
 
-            for msg_handlers.iter().advance |handler| {
+            for handler in msg_handlers.iter() {
                 (*handler)(&msg)
             }
 
@@ -210,7 +211,7 @@ impl ImageCache {
                 // Wait until we have no outstanding requests and subtasks
                 // before exiting
                 let mut can_exit = true;
-                for self.state_map.each_value |state| {
+                for (_, state) in self.state_map.iter() {
                     match *state {
                         Prefetching(*) => can_exit = false,
                         Decoding => can_exit = false,
@@ -231,37 +232,37 @@ impl ImageCache {
         }
     }
 
-    priv fn get_state(&self, url: Url) -> ImageState {
+    fn get_state(&self, url: Url) -> ImageState {
         match self.state_map.find(&url) {
             Some(state) => *state,
             None => Init
         }
     }
 
-    priv fn set_state(&self, url: Url, state: ImageState) {
+    fn set_state(&self, url: Url, state: ImageState) {
         self.state_map.insert(url, state);
     }
 
-    priv fn prefetch(&self, url: Url) {
-        match self.get_state(copy url) {
+    fn prefetch(&self, url: Url) {
+        match self.get_state(url.clone()) {
             Init => {
                 let to_cache = self.chan.clone();
                 let resource_task = self.resource_task.clone();
-                let url_cell = Cell::new(copy url);
+                let url_cell = Cell::new(url.clone());
 
                 do spawn {
                     let url = url_cell.take();
                     debug!("image_cache_task: started fetch for %s", url.to_str());
 
-                    let image = load_image_data(copy url, resource_task.clone());
+                    let image = load_image_data(url.clone(), resource_task.clone());
 
                     let result = if image.is_ok() {
-                        Ok(Cell::new(result::unwrap(image)))
+                        Ok(Cell::new(image.unwrap()))
                     } else {
                         Err(())
                     };
-                    to_cache.send(StorePrefetchedImageData(copy url, result));
-                    debug!("image_cache_task: ended fetch for %s", (copy url).to_str());
+                    to_cache.send(StorePrefetchedImageData(url.clone(), result));
+                    debug!("image_cache_task: ended fetch for %s", (url.clone()).to_str());
                 }
 
                 self.set_state(url, Prefetching(DoNotDecode));
@@ -273,20 +274,20 @@ impl ImageCache {
         }
     }
 
-    priv fn store_prefetched_image_data(&self, url: Url, data: Result<Cell<~[u8]>, ()>) {
-        match self.get_state(copy url) {
+    fn store_prefetched_image_data(&self, url: Url, data: Result<Cell<~[u8]>, ()>) {
+        match self.get_state(url.clone()) {
           Prefetching(next_step) => {
             match data {
               Ok(data_cell) => {
                 let data = data_cell.take();
-                self.set_state(copy url, Prefetched(@Cell::new(data)));
+                self.set_state(url.clone(), Prefetched(@Cell::new(data)));
                 match next_step {
                   DoDecode => self.decode(url),
                   _ => ()
                 }
               }
               Err(*) => {
-                self.set_state(copy url, Failed);
+                self.set_state(url.clone(), Failed);
                 self.purge_waiters(url, || ImageFailed);
               }
             }
@@ -302,8 +303,8 @@ impl ImageCache {
         }
     }
 
-    priv fn decode(&self, url: Url) {
-        match self.get_state(copy url) {
+    fn decode(&self, url: Url) {
+        match self.get_state(url.clone()) {
             Init => fail!(~"decoding image before prefetch"),
 
             Prefetching(DoNotDecode) => {
@@ -320,7 +321,7 @@ impl ImageCache {
 
                 let data = data_cell.take();
                 let to_cache = self.chan.clone();
-                let url_cell = Cell::new(copy url);
+                let url_cell = Cell::new(url.clone());
                 let decode = (self.decoder_factory)();
 
                 do spawn {
@@ -328,11 +329,11 @@ impl ImageCache {
                     debug!("image_cache_task: started image decode for %s", url.to_str());
                     let image = decode(data);
                     let image = if image.is_some() {
-                        Some(ARC(~image.unwrap()))
+                        Some(Arc::new(~image.unwrap()))
                     } else {
                         None
                     };
-                    to_cache.send(StoreImage(copy url, image));
+                    to_cache.send(StoreImage(url.clone(), image));
                     debug!("image_cache_task: ended image decode for %s", url.to_str());
                 }
 
@@ -345,17 +346,17 @@ impl ImageCache {
         }
     }
 
-    priv fn store_image(&self, url: Url, image: Option<ARC<~Image>>) {
+    fn store_image(&self, url: Url, image: Option<Arc<~Image>>) {
 
-        match self.get_state(copy url) {
+        match self.get_state(url.clone()) {
           Decoding => {
             match image {
               Some(image) => {
-                self.set_state(copy url, Decoded(@image.clone()));
+                self.set_state(url.clone(), Decoded(@image.clone()));
                 self.purge_waiters(url, || ImageReady(image.clone()) );
               }
               None => {
-                self.set_state(copy url, Failed);
+                self.set_state(url.clone(), Failed);
                 self.purge_waiters(url, || ImageFailed );
               }
             }
@@ -372,10 +373,10 @@ impl ImageCache {
 
     }
 
-    priv fn purge_waiters(&self, url: Url, f: &fn() -> ImageResponseMsg) {
+    fn purge_waiters(&self, url: Url, f: &fn() -> ImageResponseMsg) {
         match self.wait_map.pop(&url) {
             Some(waiters) => {
-                for waiters.iter().advance |response| {
+                for response in waiters.iter() {
                     response.send(f());
                 }
             }
@@ -383,8 +384,8 @@ impl ImageCache {
         }
     }
 
-    priv fn get_image(&self, url: Url, response: Chan<ImageResponseMsg>) {
-        match self.get_state(copy url) {
+    fn get_image(&self, url: Url, response: Chan<ImageResponseMsg>) {
+        match self.get_state(url.clone()) {
             Init => fail!(~"request for image before prefetch"),
             Prefetching(DoDecode) => response.send(ImageNotReady),
             Prefetching(DoNotDecode) | Prefetched(*) => fail!(~"request for image before decode"),
@@ -394,8 +395,8 @@ impl ImageCache {
         }
     }
 
-    priv fn wait_for_image(&self, url: Url, response: Chan<ImageResponseMsg>) {
-        match self.get_state(copy url) {
+    fn wait_for_image(&self, url: Url, response: Chan<ImageResponseMsg>) {
+        match self.get_state(url.clone()) {
             Init => fail!(~"request for image before prefetch"),
 
             Prefetching(DoNotDecode) | Prefetched(*) => fail!(~"request for image before decode"),
@@ -541,7 +542,7 @@ fn should_fail_if_requesting_image_before_requesting_decode() {
     let image_cache_task = ImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
     // no decode message
 
     let (chan, _port) = stream();
@@ -564,7 +565,7 @@ fn should_not_request_url_from_resource_task_on_multiple_prefetches() {
     let image_cache_task = ImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
     image_cache_task.send(Prefetch(url));
     url_requested.recv();
     image_cache_task.exit();
@@ -587,8 +588,8 @@ fn should_return_image_not_ready_if_data_has_not_arrived() {
     let image_cache_task = ImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
     let (response_chan, response_port) = stream();
     image_cache_task.send(GetImage(url, response_chan));
     assert!(response_port.recv() == ImageNotReady);
@@ -617,8 +618,8 @@ fn should_return_decoded_image_data_if_data_has_arrived() {
         }
     }));
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     wait_for_image_chan.recv();
@@ -654,15 +655,15 @@ fn should_return_decoded_image_data_for_multiple_requests() {
         }
     }));
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     wait_for_image.recv();
 
-    for iter::repeat(2) {
+    for _ in iter::repeat(2) {
         let (response_chan, response_port) = stream();
-        image_cache_task.send(GetImage(copy url, response_chan));
+        image_cache_task.send(GetImage(url.clone(), response_chan));
         match response_port.recv() {
           ImageReady(_) => (),
           _ => fail
@@ -700,12 +701,12 @@ fn should_not_request_image_from_resource_task_if_image_is_already_available() {
     let image_cache_task = ImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     image_bin_sent.recv();
 
-    image_cache_task.send(Prefetch(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
 
     image_cache_task.exit();
     mock_resource_task.send(resource_task::Exit);
@@ -744,14 +745,14 @@ fn should_not_request_image_from_resource_task_if_image_fetch_already_failed() {
     let image_cache_task = ImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     image_bin_sent.recv();
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     image_cache_task.exit();
     mock_resource_task.send(resource_task::Exit);
@@ -784,8 +785,8 @@ fn should_return_failed_if_image_bin_cannot_be_fetched() {
         }
     }));
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     wait_for_prefetech.recv();
@@ -822,14 +823,14 @@ fn should_return_failed_for_multiple_get_image_requests_if_image_bin_cannot_be_f
         }
     }));
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     wait_for_prefetech.recv();
 
     let (response_chan, response_port) = stream();
-    image_cache_task.send(GetImage(copy url, response_chan));
+    image_cache_task.send(GetImage(url.clone(), response_chan));
     match response_port.recv() {
       ImageFailed => (),
       _ => fail
@@ -879,8 +880,8 @@ fn should_return_not_ready_if_image_is_still_decoding() {
         }
     }));
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     wait_for_prefetech.recv();
@@ -922,8 +923,8 @@ fn should_return_failed_if_image_decode_fails() {
         }
     }));
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     wait_for_decode.recv();
@@ -961,8 +962,8 @@ fn should_return_image_on_wait_if_image_is_already_loaded() {
         }
     }));
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     // Wait until our mock resource task has sent the image to the image cache
     wait_for_decode.recv();
@@ -991,8 +992,8 @@ fn should_return_image_on_wait_if_image_is_not_yet_loaded() {
     let image_cache_task = ImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     let (response_chan, response_port) = stream();
     image_cache_task.send(WaitForImage(url, response_chan));
@@ -1021,8 +1022,8 @@ fn should_return_image_failed_on_wait_if_image_fails_to_load() {
     let image_cache_task = ImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     let (response_chan, response_port) = stream();
     image_cache_task.send(WaitForImage(url, response_chan));
@@ -1048,8 +1049,8 @@ fn sync_cache_should_wait_for_images() {
     let image_cache_task = SyncImageCacheTask(mock_resource_task);
     let url = make_url(~"file", None);
 
-    image_cache_task.send(Prefetch(copy url));
-    image_cache_task.send(Decode(copy url));
+    image_cache_task.send(Prefetch(url.clone()));
+    image_cache_task.send(Decode(url.clone()));
 
     let (response_chan, response_port) = stream();
     image_cache_task.send(GetImage(url, response_chan));
diff --git a/src/components/net/local_image_cache.rs b/src/components/net/local_image_cache.rs
index 335d2c6dd26..9c6bf12191c 100644
--- a/src/components/net/local_image_cache.rs
+++ b/src/components/net/local_image_cache.rs
@@ -15,7 +15,7 @@ use std::comm;
 use std::comm::Port;
 use std::task;
 use servo_util::url::{UrlMap, url_map};
-use extra::net::url::Url;
+use extra::url::Url;
 
 pub fn LocalImageCache(image_cache_task: ImageCacheTask) -> LocalImageCache {
     LocalImageCache {
@@ -33,14 +33,13 @@ pub struct LocalImageCache {
     priv state_map: UrlMap<@mut ImageState>
 }
 
-priv struct ImageState {
+struct ImageState {
     prefetched: bool,
     decoded: bool,
     last_request_round: uint,
     last_response: ImageResponseMsg
 }
 
-#[allow(non_implicitly_copyable_typarams)] // Using maps of Urls
 impl LocalImageCache {
     /// The local cache will only do a single remote request for a given
     /// URL in each 'round'. Layout should call this each time it begins
@@ -52,7 +51,7 @@ impl LocalImageCache {
     pub fn prefetch(&self, url: &Url) {
         let state = self.get_state(url);
         if !state.prefetched {
-            self.image_cache_task.send(Prefetch(copy *url));
+            self.image_cache_task.send(Prefetch((*url).clone()));
             state.prefetched = true;
         }
     }
@@ -60,7 +59,7 @@ impl LocalImageCache {
     pub fn decode(&self, url: &Url) {
         let state = self.get_state(url);
         if !state.decoded {
-            self.image_cache_task.send(Decode(copy *url));
+            self.image_cache_task.send(Decode((*url).clone()));
             state.decoded = true;
         }
     }
@@ -98,7 +97,7 @@ impl LocalImageCache {
         }
 
         let (response_port, response_chan) = comm::stream();
-        self.image_cache_task.send(GetImage(copy *url, response_chan));
+        self.image_cache_task.send(GetImage((*url).clone(), response_chan));
 
         let response = response_port.recv();
         match response {
@@ -110,11 +109,11 @@ impl LocalImageCache {
                 // on the image to load and triggering layout
                 let image_cache_task = self.image_cache_task.clone();
                 assert!(self.on_image_available.is_some());
-                let on_image_available = self.on_image_available.get()();
-                let url = copy *url;
+                let on_image_available = self.on_image_available.unwrap()();
+                let url = (*url).clone();
                 do task::spawn {
                     let (response_port, response_chan) = comm::stream();
-                    image_cache_task.send(WaitForImage(copy url, response_chan));
+                    image_cache_task.send(WaitForImage(url.clone(), response_chan));
                     on_image_available(response_port.recv());
                 }
             }
@@ -134,7 +133,7 @@ impl LocalImageCache {
         return port;
     }
 
-    priv fn get_state(&self, url: &Url) -> @mut ImageState {
+    fn get_state(&self, url: &Url) -> @mut ImageState {
         let state = do self.state_map.find_or_insert_with(url.clone()) |_| {
             let new_state = @mut ImageState {
                 prefetched: false,
diff --git a/src/components/net/net.rc b/src/components/net/net.rc
index a646de09315..f53f215c8aa 100644
--- a/src/components/net/net.rc
+++ b/src/components/net/net.rc
@@ -9,7 +9,7 @@
 #[crate_type = "lib"];
 
 extern mod geom;
-extern mod http_client;
+//extern mod http_client;
 extern mod servo_util (name = "util");
 extern mod stb_image;
 extern mod extra;
@@ -25,7 +25,7 @@ pub mod image {
 }
 
 pub mod file_loader;
-pub mod http_loader;
+//pub mod http_loader;
 pub mod image_cache_task;
 pub mod local_image_cache;
 pub mod resource_task;
diff --git a/src/components/net/resource_task.rs b/src/components/net/resource_task.rs
index 457cd6dfd35..e2ce236dc80 100644
--- a/src/components/net/resource_task.rs
+++ b/src/components/net/resource_task.rs
@@ -5,11 +5,11 @@
 //! A task that takes a URL and streams back the binary data.
 
 use file_loader;
-use http_loader;
+//use http_loader;
 
 use std::cell::Cell;
 use std::comm::{Chan, Port, SharedChan};
-use extra::net::url::{Url, to_str};
+use extra::url::Url;
 use util::spawn_listener;
 
 pub enum ControlMsg {
@@ -43,10 +43,10 @@ pub type LoaderTask = ~fn(url: Url, Chan<ProgressMsg>);
 /// Create a ResourceTask with the default loaders
 pub fn ResourceTask() -> ResourceTask {
     let file_loader_factory: LoaderTaskFactory = file_loader::factory;
-    let http_loader_factory: LoaderTaskFactory = http_loader::factory;
+    //let http_loader_factory: LoaderTaskFactory = http_loader::factory;
     let loaders = ~[
         (~"file", file_loader_factory),
-        (~"http", http_loader_factory)
+        //(~"http", http_loader_factory)
     ];
     create_resource_task_with_loaders(loaders)
 }
@@ -94,7 +94,7 @@ impl ResourceManager {
 
         match self.get_loader_factory(&url) {
             Some(loader_factory) => {
-                debug!("resource_task: loading url: %s", to_str(&url));
+                debug!("resource_task: loading url: %s", url.to_str());
                 loader_factory(url, progress_chan);
             }
             None => {
@@ -105,7 +105,7 @@ impl ResourceManager {
     }
 
     fn get_loader_factory(&self, url: &Url) -> Option<LoaderTask> {
-        for self.loaders.iter().advance |scheme_loader| {
+        for scheme_loader in self.loaders.iter() {
             match *scheme_loader {
                 (ref scheme, ref loader_factory) => {
 	            if (*scheme) == url.scheme {
@@ -142,7 +142,7 @@ fn test_bad_scheme() {
 fn should_delegate_to_scheme_loader() {
     let payload = ~[1, 2, 3];
     let loader_factory = |_url: Url, progress_chan: Chan<ProgressMsg>| {
-        progress_chan.send(Payload(copy payload));
+        progress_chan.send(Payload(payload.clone()));
         progress_chan.send(Done(Ok(())));
     };
     let loader_factories = ~[(~"snicklefritz", loader_factory)];
diff --git a/src/components/script/dom/bindings/codegen/CodegenRust.py b/src/components/script/dom/bindings/codegen/CodegenRust.py
index 140a712b950..22bd6ca6db3 100644
--- a/src/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/src/components/script/dom/bindings/codegen/CodegenRust.py
@@ -1044,7 +1044,7 @@ for (uint32_t i = 0; i < length; ++i) {
             #    "if (!ConvertJSValueToString(cx, ${val}, ${valPtr}, %s, %s, %s)) {\n"
             #    "  return false;\n"
             #    "}" % (nullBehavior, undefinedBehavior, varName))
-            strval = "str(strval.get())"
+            strval = "str(strval.unwrap())"
             if isOptional:
                 strval = "Some(%s)" % strval
             conversionCode = (
@@ -1114,7 +1114,7 @@ for (uint32_t i = 0; i < length; ++i) {
             "  if result.is_err() {\n"
             "%(handleInvalidEnumValueCode)s"
             "  }\n"
-            "  let index = result.get();\n"
+            "  let index = result.unwrap();\n"
             "  ${declName} = cast::transmute(index); //XXXjdm need some range checks up in here\n"
             "}" % { "enumtype" : enum,
                       "values" : enum + "Values::strings",
@@ -1511,7 +1511,7 @@ for (uint32_t i = 0; i < length; ++i) {
             wrappingCode = ("if %s.is_none() {\n" % (result) +
                             CGIndenter(CGGeneric(setValue("JSVAL_NULL"))).define() + "\n" +
                             "}\n" +
-                            "let mut %s = %s.get();\n" % (result, result))
+                            "let mut %s = %s.unwrap();\n" % (result, result))
         else:
             wrappingCode = ""
         if (not descriptor.interface.isExternal() and
@@ -2746,10 +2746,10 @@ class CGGetPerInterfaceObject(CGAbstractMethod):
   }*/
   /* Check to see whether the interface objects are already installed */
   let protoOrIfaceArray: *mut *JSObject = cast::transmute(GetProtoOrIfaceArray(aGlobal));
-  let cachedObject: *JSObject = *protoOrIfaceArray.offset(%s as uint);
+  let cachedObject: *JSObject = *protoOrIfaceArray.offset(%s as int);
   if cachedObject.is_null() {
     let tmp: *JSObject = CreateInterfaceObjects(aCx, aGlobal, aReceiver);
-    *protoOrIfaceArray.offset(%s as uint) = tmp;
+    *protoOrIfaceArray.offset(%s as int) = tmp;
     tmp
   } else {
     cachedObject
@@ -3623,7 +3623,7 @@ class CGDOMJSProxyHandler_getOwnPropertyDescriptor(CGAbstractExternMethod):
             templateValues = {'jsvalRef': '(*desc).value', 'jsvalPtr': 'ptr::to_mut_unsafe_ptr(&mut (*desc).value)',
                               'obj': 'proxy', 'successCode': fillDescriptor}
             get = ("if index.is_some() {\n" +
-                   "  let index = index.get();\n" +
+                   "  let index = index.unwrap();\n" +
                    "  let this: *%s = UnwrapProxy(proxy);\n" +
                    CGIndenter(CGProxyIndexedGetter(self.descriptor, templateValues)).define() + "\n" +
                    "}\n") % (self.descriptor.concreteType)
@@ -3632,7 +3632,7 @@ class CGDOMJSProxyHandler_getOwnPropertyDescriptor(CGAbstractExternMethod):
             setOrIndexedGet += "if set != 0 {\n"
             if indexedSetter:
                 setOrIndexedGet += ("  if index.is_some() {\n" +
-                                    "    let index = index.get();\n")
+                                    "    let index = index.unwrap();\n")
                 if not 'IndexedCreator' in self.descriptor.operations:
                     # FIXME need to check that this is a 'supported property index'
                     assert False
@@ -3677,7 +3677,7 @@ class CGDOMJSProxyHandler_getOwnPropertyDescriptor(CGAbstractExternMethod):
                         "  if strval.is_err() {\n" +
                         "    return 0;\n" +
                         "  }\n" +
-                        "  let name = str(strval.get());\n" +
+                        "  let name = str(strval.unwrap());\n" +
                         "\n" +
                         "  let this: *%s = UnwrapProxy(proxy);\n" +
                         CGIndenter(CGProxyNamedGetter(self.descriptor, templateValues)).define() + "\n" +
@@ -3721,7 +3721,7 @@ class CGDOMJSProxyHandler_defineProperty(CGAbstractExternMethod):
                 raise TypeError("Can't handle creator that's different from the setter")
             set += ("let index = GetArrayIndexFromId(cx, id);\n" +
                     "if index.is_some() {\n" +
-                    "  let index = index.get();\n" +
+                    "  let index = index.unwrap();\n" +
                     "  let this: *%s = UnwrapProxy(proxy);\n" +
                     CGIndenter(CGProxyIndexedSetter(self.descriptor)).define() +
                     "  return 1;\n" +
@@ -3746,7 +3746,7 @@ class CGDOMJSProxyHandler_defineProperty(CGAbstractExternMethod):
                     "  if strval.is_err() {\n" +
                     "    return 0;\n" +
                     "  }\n" +
-                    "  let name = str(strval.get());\n" +
+                    "  let name = str(strval.unwrap());\n" +
                     "\n" +
                     "  let this: *%s = UnwrapProxy(proxy);\n" +
                     CGIndenter(CGProxyNamedSetter(self.descriptor)).define() + "\n" +
@@ -3762,7 +3762,7 @@ class CGDOMJSProxyHandler_defineProperty(CGAbstractExternMethod):
                     "  if strval.is_err() {\n" +
                     "    return 0;\n" +
                     "  }\n" +
-                    "  let name = str(strval.get());\n" +
+                    "  let name = str(strval.unwrap());\n" +
                     "  let this: %%s = UnwrapProxy(proxy);\n" +
                     CGIndenter(CGProxyNamedGetter(self.descriptor)).define() +
                     "  if (found) {\n"
@@ -3787,7 +3787,7 @@ class CGDOMJSProxyHandler_hasOwn(CGAbstractExternMethod):
         if indexedGetter:
             indexed = ("let index = GetArrayIndexFromId(cx, id);\n" +
                        "if index.is_some() {\n" +
-                       "  let index = index.get();\n" +
+                       "  let index = index.unwrap();\n" +
                        "  let this: *%s = UnwrapProxy(proxy);\n" +
                        CGIndenter(CGProxyIndexedGetter(self.descriptor)).define() + "\n" +
                        "  *bp = found as JSBool;\n" +
@@ -3808,7 +3808,7 @@ class CGDOMJSProxyHandler_hasOwn(CGAbstractExternMethod):
                      "  if strval.is_err() {\n" +
                      "    return 0;\n" +
                      "  }\n" +
-                     "  let name = str(strval.get());\n" +
+                     "  let name = str(strval.unwrap());\n" +
                      "\n" +
                      "  let this: *%s = UnwrapProxy(proxy);\n" +
                      CGIndenter(CGProxyNamedGetter(self.descriptor)).define() + "\n" +
@@ -3861,7 +3861,7 @@ if expando.is_not_null() {
         if indexedGetter:
             getIndexedOrExpando = ("let index = GetArrayIndexFromId(cx, id);\n" +
                                    "if index.is_some() {\n" +
-                                   "  let index = index.get();\n" +
+                                   "  let index = index.unwrap();\n" +
                                    "  let this = UnwrapProxy(proxy);\n" +
                                    CGIndenter(CGProxyIndexedGetter(self.descriptor, templateValues)).define())
             getIndexedOrExpando += """
@@ -3935,7 +3935,7 @@ class CGDOMJSProxyHandler_obj_toString(CGAbstractExternMethod):
 JSString* jsresult;
 return xpc_qsStringToJsstring(cx, result, &jsresult) ? jsresult : NULL;""" 
 
-        return """    do str::as_c_str("%s") |s| {
+        return """    do "%s".to_c_str().with_ref |s| {
       _obj_toString(cx, s)
     }""" % self.descriptor.name
 
@@ -4461,9 +4461,9 @@ class CGDictionary(CGThing):
         # NOTE: jsids are per-runtime, so don't use them in workers
         if True or self.workers: #XXXjdm hack until 'static mut' exists for global jsids
             propName = member.identifier.name
-            propCheck = ('str::as_c_str("%s", |s| { JS_HasProperty(cx, RUST_JSVAL_TO_OBJECT(val), s, ptr::to_unsafe_ptr(&found)) })' %
+            propCheck = ('"%s".to_c_str().with_ref(|s| { JS_HasProperty(cx, RUST_JSVAL_TO_OBJECT(val), s, ptr::to_unsafe_ptr(&found)) })' %
                          propName)
-            propGet = ('str::as_c_str("%s", |s| { JS_GetProperty(cx, RUST_JSVAL_TO_OBJECT(val), s, ptr::to_unsafe_ptr(&temp)) })' %
+            propGet = ('"%s".to_c_str().with_ref(|s| { JS_GetProperty(cx, RUST_JSVAL_TO_OBJECT(val), s, ptr::to_unsafe_ptr(&temp)) })' %
                        propName)
         else:
             propId = self.makeIdName(member.identifier.name);
diff --git a/src/components/script/dom/bindings/element.rs b/src/components/script/dom/bindings/element.rs
index a177c10c332..8ca841772de 100644
--- a/src/components/script/dom/bindings/element.rs
+++ b/src/components/script/dom/bindings/element.rs
@@ -21,8 +21,6 @@ use std::libc::c_uint;
 use std::comm;
 use std::ptr;
 use std::ptr::null;
-use std::result;
-use std::str;
 use js::glue::*;
 use js::jsapi::*;
 use js::jsapi::{JSContext, JSVal, JSObject, JSBool, JSFreeOp, JSPropertySpec};
@@ -49,14 +47,14 @@ pub extern fn trace(tracer: *mut JSTracer, obj: *JSObject) {
             return;
         }
         error!("tracing %s", name);
-        let mut node = node.get();
+        let mut node = node.unwrap();
         let cache = node.get_wrappercache();
         let wrapper = cache.get_wrapper();
         assert!(wrapper.is_not_null());
         unsafe {
             (*tracer).debugPrinter = ptr::null();
             (*tracer).debugPrintIndex = -1;
-            do str::as_c_str(name) |name| {
+            do name.to_c_str().with_ref |name| {
                 (*tracer).debugPrintArg = name as *libc::c_void;
                 JS_CallTracer(cast::transmute(tracer), wrapper, JSTRACE_OBJECT as u32);
             }
@@ -194,14 +192,14 @@ extern fn setAttribute(cx: *JSContext, argc: c_uint, vp: *JSVal) -> JSBool {
         if strval.is_err() {
             return 0;
         }
-        arg0 = str(strval.get());
+        arg0 = str(strval.unwrap());
 
         let arg1: DOMString;
         let strval = jsval_to_str(cx, (*argv.offset(1)));
         if strval.is_err() {
             return 0;
         }
-        arg1 = str(strval.get());
+        arg1 = str(strval.unwrap());
 
         do node.as_mut_element |elem| {
             elem.set_attr(&arg0, &arg1);
@@ -211,7 +209,6 @@ extern fn setAttribute(cx: *JSContext, argc: c_uint, vp: *JSVal) -> JSBool {
     }
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 extern fn HTMLImageElement_getWidth(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool {
     unsafe {
         let obj = JS_THIS_OBJECT(cx, cast::transmute(vp));
@@ -241,7 +238,6 @@ extern fn HTMLImageElement_getWidth(cx: *JSContext, _argc: c_uint, vp: *mut JSVa
     }
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 extern fn HTMLImageElement_setWidth(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool {
     unsafe {
         let obj = JS_THIS_OBJECT(cx, cast::transmute(vp));
@@ -275,7 +271,7 @@ extern fn getTagName(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool {
 
         let node = unwrap(obj);
         do node.with_imm_element |elem| {
-            let s = str(copy elem.tag_name);
+            let s = str(elem.tag_name.clone());
             *vp = domstring_to_jsval(cx, &s);            
         }
     }
@@ -295,9 +291,9 @@ pub fn create(cx: *JSContext, node: &mut AbstractNode<ScriptView>) -> jsobj {
     //XXXjdm the parent should probably be the node parent instead of the global
     //TODO error checking
     let compartment = utils::get_compartment(cx);
-    let obj = result::unwrap(compartment.new_object_with_proto(~"GenericElementInstance",
-                                                               proto,
-                                                               compartment.global_obj.ptr));
+    let obj = compartment.new_object_with_proto(~"GenericElementInstance",
+                                                proto,
+                                                compartment.global_obj.ptr).unwrap();
 
     let cache = node.get_wrappercache();
     assert!(cache.get_wrapper().is_null());
diff --git a/src/components/script/dom/bindings/node.rs b/src/components/script/dom/bindings/node.rs
index b8351ced73c..bfa153ff9c2 100644
--- a/src/components/script/dom/bindings/node.rs
+++ b/src/components/script/dom/bindings/node.rs
@@ -97,7 +97,6 @@ macro_rules! generate_element(
     })
 )
 
-#[allow(non_implicitly_copyable_typarams)]
 pub fn create(cx: *JSContext, node: &mut AbstractNode<ScriptView>) -> *JSObject {
     match node.type_id() {
         ElementNodeTypeId(HTMLElementTypeId) => generate_element!(HTMLElement),
@@ -138,7 +137,6 @@ pub unsafe fn unwrap(obj: *JSObject) -> AbstractNode<ScriptView> {
     AbstractNode::from_raw(raw)
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 extern fn getFirstChild(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool {
     unsafe {
         let obj = JS_THIS_OBJECT(cx, cast::transmute(vp));
@@ -160,7 +158,6 @@ extern fn getFirstChild(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool
     return 1;
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 extern fn getNextSibling(cx: *JSContext, _argc: c_uint, vp: *mut JSVal) -> JSBool {
     unsafe {
         let obj = JS_THIS_OBJECT(cx, cast::transmute(vp));
diff --git a/src/components/script/dom/bindings/proxyhandler.rs b/src/components/script/dom/bindings/proxyhandler.rs
index fef04d6fee9..2aac4a14918 100644
--- a/src/components/script/dom/bindings/proxyhandler.rs
+++ b/src/components/script/dom/bindings/proxyhandler.rs
@@ -68,7 +68,7 @@ pub extern fn defineProperty(cx: *JSContext, proxy: *JSObject, id: jsid,
 
 pub fn _obj_toString(cx: *JSContext, className: *libc::c_char) -> *JSString {
   unsafe {
-    let name = str::raw::from_buf(className as *u8);
+    let name = str::raw::from_c_str(className);
     let nchars = "[object ]".len() + name.len();
     let chars: *mut jschar = cast::transmute(JS_malloc(cx, (nchars + 1) as u64 * (size_of::<jschar>() as u64)));
     if chars.is_null() {
@@ -76,10 +76,10 @@ pub fn _obj_toString(cx: *JSContext, className: *libc::c_char) -> *JSString {
     }
 
     let result = ~"[object " + name + "]";
-    for result.iter().enumerate().advance |(i, c)| {
-      *chars.offset(i) = c as jschar;
+    for (i, c) in result.iter().enumerate() {
+      *chars.offset(i as int) = c as jschar;
     }
-    *chars.offset(nchars) = 0;
+    *chars.offset(nchars as int) = 0;
     let jsstr = JS_NewUCString(cx, cast::transmute(chars), nchars as u64);
     if jsstr.is_null() {
         JS_free(cx, cast::transmute(chars));
diff --git a/src/components/script/dom/bindings/text.rs b/src/components/script/dom/bindings/text.rs
index 2ec4a6a69df..efa8cc90206 100644
--- a/src/components/script/dom/bindings/text.rs
+++ b/src/components/script/dom/bindings/text.rs
@@ -16,7 +16,6 @@ use js::rust::{Compartment, jsobj};
 
 use std::cast;
 use std::libc;
-use std::result;
 
 extern fn finalize_text(_fop: *JSFreeOp, obj: *JSObject) {
     debug!("text finalize: %?!", obj as uint);
@@ -79,9 +78,9 @@ pub fn create(cx: *JSContext, node: &mut AbstractNode<ScriptView>) -> jsobj {
     //XXXjdm the parent should probably be the node parent instead of the global
     //TODO error checking
     let compartment = utils::get_compartment(cx);
-    let obj = result::unwrap(compartment.new_object_with_proto(instance,
-                                                               proto,
-                                                               compartment.global_obj.ptr));
+    let obj = compartment.new_object_with_proto(instance,
+                                                proto,
+                                                compartment.global_obj.ptr).unwrap();
 
     let cache = node.get_wrappercache();
     assert!(cache.get_wrapper().is_null());
diff --git a/src/components/script/dom/bindings/utils.rs b/src/components/script/dom/bindings/utils.rs
index 728c1eb112e..057f6d6ef97 100644
--- a/src/components/script/dom/bindings/utils.rs
+++ b/src/components/script/dom/bindings/utils.rs
@@ -13,9 +13,7 @@ use std::hashmap::HashMap;
 use std::libc;
 use std::ptr;
 use std::ptr::{null, to_unsafe_ptr};
-use std::result;
 use std::str;
-use std::uint;
 use std::unstable::intrinsics;
 use js::glue::*;
 use js::glue::{DefineFunctionWithReserved, GetObjectJSClass, RUST_OBJECT_TO_JSVAL};
@@ -85,7 +83,7 @@ extern fn InterfaceObjectToString(cx: *JSContext, _argc: uint, vp: *mut JSVal) -
         return 0;
     }
 
-    let name = jsval_to_str(cx, *v).get();
+    let name = jsval_to_str(cx, *v).unwrap();
     let retval = str(~"function " + name + "() {\n    [native code]\n}");
     *vp = domstring_to_jsval(cx, &retval);
     return 1;
@@ -204,7 +202,7 @@ pub fn jsval_to_str(cx: *JSContext, v: JSVal) -> Result<~str, ()> {
         }
 
         let strbuf = JS_EncodeString(cx, jsstr);
-        let buf = str::raw::from_buf(strbuf as *u8);
+        let buf = str::raw::from_c_str(strbuf);
         JS_free(cx, strbuf as *libc::c_void);
         Ok(buf)
     }
@@ -216,10 +214,10 @@ pub unsafe fn domstring_to_jsval(cx: *JSContext, string: &DOMString) -> JSVal {
         JSVAL_NULL
       }
       &str(ref s) => {
-        str::as_buf(*s, |buf, len| {
+        do s.as_imm_buf |buf, len| {
             let cbuf = cast::transmute(buf);
             RUST_STRING_TO_JSVAL(JS_NewStringCopyN(cx, cbuf, len as libc::size_t))
-        })
+        }
       }
     }
 }
@@ -322,13 +320,13 @@ pub fn define_empty_prototype(name: ~str, proto: Option<~str>, compartment: @mut
     compartment.register_class(prototype_jsclass(name.to_owned()));
 
     //TODO error checking
-    let obj = result::unwrap(
+    let obj = (
         match proto {
             Some(s) => compartment.new_object_with_proto(name.to_owned(),
                                                          s, 
                                                          compartment.global_obj.ptr),
             None => compartment.new_object(name.to_owned(), null(), compartment.global_obj.ptr)
-        });
+        }).unwrap();
 
     unsafe {
         compartment.define_property(name.to_owned(), RUST_OBJECT_TO_JSVAL(obj.ptr),
@@ -392,6 +390,7 @@ pub struct JSNativeHolder {
     propertyHooks: *NativePropertyHooks
 }
 
+#[deriving(Clone)]
 pub enum ConstantVal {
     IntVal(i32),
     UintVal(u32),
@@ -401,6 +400,7 @@ pub enum ConstantVal {
     VoidVal
 }
 
+#[deriving(Clone)]
 pub struct ConstantSpec {
     name: *libc::c_char,
     value: ConstantVal
@@ -454,7 +454,7 @@ pub fn CreateInterfaceObjects2(cx: *JSContext, global: *JSObject, receiver: *JSO
 
     let mut interface = ptr::null();
     if constructorClass.is_not_null() || constructor.is_not_null() {
-        interface = do str::as_c_str(name) |s| {
+        interface = do name.to_c_str().with_ref |s| {
             CreateInterfaceObject(cx, global, receiver, constructorClass,
                                   constructor, ctorNargs, proto,
                                   staticMethods, constants, s)
@@ -506,7 +506,7 @@ fn CreateInterfaceObject(cx: *JSContext, global: *JSObject, receiver: *JSObject,
         }
 
         if constructorClass.is_not_null() {
-            let toString = do str::as_c_str("toString") |s| {
+            let toString = do "toString".to_c_str().with_ref |s| {
                 DefineFunctionWithReserved(cx, constructor, s,
                                            InterfaceObjectToString,
                                            0, 0)
@@ -666,7 +666,7 @@ impl WrapperCache {
 }
 
 pub fn WrapNewBindingObject(cx: *JSContext, scope: *JSObject,
-                            mut value: @mut CacheableWrapper,
+                            value: @mut CacheableWrapper,
                             vp: *mut JSVal) -> bool {
   unsafe {
     let cache = value.get_wrappercache();
@@ -765,7 +765,7 @@ pub fn XrayResolveProperty(cx: *JSContext,
   unsafe {
     match attributes {
         Some(attrs) => {
-            for attrs.iter().advance |&elem| {
+            for &elem in attrs.iter() {
                 let (attr, attr_id) = elem;
                 if attr_id == JSID_VOID || attr_id != id {
                     loop;
@@ -815,20 +815,18 @@ fn InternJSString(cx: *JSContext, chars: *libc::c_char) -> Option<jsid> {
 }
 
 pub fn InitIds(cx: *JSContext, specs: &[JSPropertySpec], ids: &mut [jsid]) -> bool {
-    let mut rval = true;
-    for specs.iter().enumerate().advance |(i, spec)| {
+    for (i, spec) in specs.iter().enumerate() {
         if spec.name.is_null() == true {
-            break;
+            return true;
         }
         match InternJSString(cx, spec.name) {
             Some(id) => ids[i] = id,
             None => {
-                rval = false;
                 return false;
             }
         }
     }
-    rval
+    true
 }
 
 pub trait DerivedWrapper {
@@ -853,6 +851,7 @@ impl DerivedWrapper for AbstractNode<ScriptView> {
     }
 }
 
+#[deriving(ToStr)]
 pub enum Error {
     FailureUnknown
 }
@@ -877,12 +876,12 @@ pub fn FindEnumStringIndex(cx: *JSContext,
         if chars.is_null() {
             return Err(());
         }
-        for values.iter().enumerate().advance |(i, value)| {
+        for (i, value) in values.iter().enumerate() {
             if value.length != length as uint {
                 loop;
             }
             let mut equal = true;
-            for uint::iterate(0, length as uint) |j| {
+            for j in range(0, length as int) {
                 if value.value[j] as u16 != *chars.offset(j) {
                     equal = false;
                     break;
diff --git a/src/components/script/dom/characterdata.rs b/src/components/script/dom/characterdata.rs
index d63fd75ec88..2d921fe07c5 100644
--- a/src/components/script/dom/characterdata.rs
+++ b/src/components/script/dom/characterdata.rs
@@ -23,7 +23,7 @@ impl CharacterData {
     }
     
     pub fn Data(&self) -> DOMString {
-        copy self.data
+        self.data.clone()
     }
 
     pub fn SetData(&mut self, arg: &DOMString, _rv: &mut ErrorResult) {
diff --git a/src/components/script/dom/clientrect.rs b/src/components/script/dom/clientrect.rs
index 5c1de65851a..a0ad4a96dc1 100644
--- a/src/components/script/dom/clientrect.rs
+++ b/src/components/script/dom/clientrect.rs
@@ -10,7 +10,6 @@ use js::jsapi::{JSObject, JSContext, JSVal};
 use js::glue::RUST_OBJECT_TO_JSVAL;
 
 use std::cast;
-use std::f32;
 
 pub struct ClientRect {
     wrapper: WrapperCache,
@@ -54,11 +53,11 @@ impl ClientRect {
     }
 
     pub fn Width(&self) -> f32 {
-        f32::abs(self.right - self.left)
+        (self.right - self.left).abs()
     }
 
     pub fn Height(&self) -> f32 {
-        f32::abs(self.bottom - self.top)
+        (self.bottom - self.top).abs()
     }
 }
 
diff --git a/src/components/script/dom/document.rs b/src/components/script/dom/document.rs
index 043eec3646a..8547a0e3cc7 100644
--- a/src/components/script/dom/document.rs
+++ b/src/components/script/dom/document.rs
@@ -18,7 +18,7 @@ use dom::htmltitleelement::HTMLTitleElement;
 
 use js::jsapi::{JS_AddObjectRoot, JS_RemoveObjectRoot, JSObject, JSContext, JSVal};
 use js::glue::RUST_OBJECT_TO_JSVAL;
-use servo_util::tree::{TreeNodeRef, TreeUtils};
+use servo_util::tree::TreeNodeRef;
 
 use std::cast;
 use std::ptr;
@@ -115,7 +115,7 @@ impl Document {
 }
 
 impl WrappableDocument for Document {
-    pub fn init_wrapper(@mut self, cx: *JSContext) {
+    fn init_wrapper(@mut self, cx: *JSContext) {
         self.wrap_object_shared(cx, ptr::null()); //XXXjdm a proper scope would be nice
     }
 }
@@ -270,11 +270,11 @@ impl Document {
                 fail!("no SVG document yet")
             },
             _ => {
-                let _ = for self.root.traverse_preorder |node| {
+                let _ = for node in self.root.traverse_preorder() {
                     if node.type_id() != ElementNodeTypeId(HTMLTitleElementTypeId) {
                         loop;
                     }
-                    for node.children().advance |child| {
+                    for child in node.children() {
                         if child.is_text() {
                             do child.with_imm_text() |text| {
                                 let s = text.parent.Data();
@@ -299,17 +299,17 @@ impl Document {
             },
             _ => {
                 let (_scope, cx) = self.get_scope_and_cx();
-                let _ = for self.root.traverse_preorder |node| {
+                let _ = for node in self.root.traverse_preorder() {
                     if node.type_id() != ElementNodeTypeId(HTMLHeadElementTypeId) {
                         loop;
                     }
                     let mut has_title = false;
-                    for node.children().advance |child| {
+                    for child in node.children() {
                         if child.type_id() != ElementNodeTypeId(HTMLTitleElementTypeId) {
                             loop;
                         }
                         has_title = true;
-                        for child.children().advance |title_child| {
+                        for title_child in child.children() {
                             child.remove_child(title_child);
                         }
                         let new_text = unsafe { 
@@ -427,7 +427,7 @@ impl Document {
     
     pub fn createHTMLCollection(&self, callback: &fn(elem: &Element) -> bool) -> @mut HTMLCollection {
         let mut elements = ~[];
-        let _ = for self.root.traverse_preorder |child| {
+        let _ = for child in self.root.traverse_preorder() {
             if child.is_element() {
                 do child.with_imm_element |elem| {
                     if callback(elem) {
@@ -441,7 +441,7 @@ impl Document {
     }
 
     pub fn content_changed(&self) {
-        for self.window.iter().advance |window| {
+        for window in self.window.iter() {
             window.content_changed()
         }
     }
diff --git a/src/components/script/dom/element.rs b/src/components/script/dom/element.rs
index 4d775577367..8e6f620c28b 100644
--- a/src/components/script/dom/element.rs
+++ b/src/components/script/dom/element.rs
@@ -47,7 +47,7 @@ use js::jsapi::{JSContext, JSObject};
 use std::cell::Cell;
 use std::comm;
 use std::str::eq_slice;
-use extra::net::url;
+use std::FromStr;
 
 pub struct Element {
     parent: Node<ScriptView>,
@@ -252,7 +252,7 @@ impl<'self> Element {
 
     pub fn get_attr(&'self self, name: &str) -> Option<&'self str> {
         // FIXME: Need an each() that links lifetimes in Rust.
-        for self.attrs.iter().advance |attr| {
+        for attr in self.attrs.iter() {
             if eq_slice(attr.name, name) {
                 let val: &str = attr.value;
                 return Some(val);
@@ -265,7 +265,7 @@ impl<'self> Element {
         let name = name.to_str();
         let value_cell = Cell::new(value.to_str());
         let mut found = false;
-        for self.attrs.mut_iter().advance |attr| {
+        for attr in self.attrs.mut_iter() {
             if eq_slice(attr.name, name) {
                 attr.value = value_cell.take().clone();
                 found = true;
@@ -279,7 +279,7 @@ impl<'self> Element {
         if "style" == name {
             self.style_attribute = Some(
                 Stylesheet::from_attribute(
-                    url::from_str("http://www.example.com/").unwrap(),
+                    FromStr::from_str("http://www.example.com/").unwrap(),
                     value.get_ref()));
         }
 
@@ -290,8 +290,8 @@ impl<'self> Element {
     }
 
     fn get_scope_and_cx(&self) -> (*JSObject, *JSContext) {
-        let doc = self.parent.owner_doc.get();
-        let win = doc.with_base(|doc| doc.window.get());
+        let doc = self.parent.owner_doc.unwrap();
+        let win = doc.with_base(|doc| doc.window.unwrap());
         let cx = unsafe {(*win.page).js_info.get_ref().js_compartment.cx.ptr};
         let cache = win.get_wrappercache();
         let scope = cache.get_wrapper();
@@ -419,7 +419,7 @@ impl Element {
                 debug!("no document");
                 None
             }
-        }.get();
+        }.unwrap();
 
         ClientRectList::new(rects, cx, scope)
     }
diff --git a/src/components/script/dom/event.rs b/src/components/script/dom/event.rs
index ca97d1bc364..78ccfa7e759 100644
--- a/src/components/script/dom/event.rs
+++ b/src/components/script/dom/event.rs
@@ -55,7 +55,7 @@ impl Event {
     }
 
     pub fn Type(&self) -> DOMString {
-        copy self.type_
+        self.type_.clone()
     }
 
     pub fn GetTarget(&self) -> Option<@mut EventTarget> {
diff --git a/src/components/script/dom/formdata.rs b/src/components/script/dom/formdata.rs
index e5e027ed4f1..873b539fdc3 100644
--- a/src/components/script/dom/formdata.rs
+++ b/src/components/script/dom/formdata.rs
@@ -39,7 +39,7 @@ impl FormData {
     pub fn Append(&mut self, name: &DOMString, value: @mut Blob, filename: Option<DOMString>) {
         let blob = BlobData {
             blob: value,
-            name: filename.get_or_default(str(~"default"))
+            name: filename.unwrap_or_default(str(~"default"))
         };
         self.data.insert(name.to_str(), blob);
     }
diff --git a/src/components/script/dom/htmldocument.rs b/src/components/script/dom/htmldocument.rs
index 52c15fc36cf..b8b56b1d850 100644
--- a/src/components/script/dom/htmldocument.rs
+++ b/src/components/script/dom/htmldocument.rs
@@ -13,7 +13,7 @@ use dom::window::Window;
 
 use js::jsapi::{JSObject, JSContext};
 
-use servo_util::tree::TreeUtils;
+use servo_util::tree::TreeNodeRef;
 
 use std::libc;
 use std::ptr;
@@ -43,7 +43,7 @@ impl HTMLDocument {
 }
 
 impl WrappableDocument for HTMLDocument {
-    pub fn init_wrapper(@mut self, cx: *JSContext) {
+    fn init_wrapper(@mut self, cx: *JSContext) {
         self.wrap_object_shared(cx, ptr::null()); //XXXjdm a proper scope would be nice
     }
 }
@@ -69,7 +69,7 @@ impl HTMLDocument {
 
     pub fn GetHead(&self) -> Option<AbstractNode<ScriptView>> {
         let mut headNode: Option<AbstractNode<ScriptView>> = None;
-        let _ = for self.parent.root.traverse_preorder |child| {
+        let _ = for child in self.parent.root.traverse_preorder() {
             if child.type_id() == ElementNodeTypeId(HTMLHeadElementTypeId) {
                 headNode = Some(child);
                 break;
diff --git a/src/components/script/dom/htmliframeelement.rs b/src/components/script/dom/htmliframeelement.rs
index ee71c2786ff..98217737a27 100644
--- a/src/components/script/dom/htmliframeelement.rs
+++ b/src/components/script/dom/htmliframeelement.rs
@@ -11,7 +11,7 @@ use geom::size::Size2D;
 use servo_msg::constellation_msg::SubpageId;
 
 use std::comm::ChanOne;
-use extra::net::url::Url;
+use extra::url::Url;
 
 pub struct HTMLIFrameElement {
     parent: HTMLElement,
diff --git a/src/components/script/dom/htmlimageelement.rs b/src/components/script/dom/htmlimageelement.rs
index b803625ebde..f345d59a8b8 100644
--- a/src/components/script/dom/htmlimageelement.rs
+++ b/src/components/script/dom/htmlimageelement.rs
@@ -4,7 +4,7 @@
 
 use dom::bindings::utils::{DOMString, null_string, ErrorResult};
 use dom::htmlelement::HTMLElement;
-use extra::net::url::Url;
+use extra::url::Url;
 
 pub struct HTMLImageElement {
     parent: HTMLElement,
diff --git a/src/components/script/dom/node.rs b/src/components/script/dom/node.rs
index 236df0f3732..e06c77577ed 100644
--- a/src/components/script/dom/node.rs
+++ b/src/components/script/dom/node.rs
@@ -20,11 +20,10 @@ use dom::window::Window;
 use std::cast;
 use std::cast::transmute;
 use std::libc::c_void;
-use std::uint;
 use js::jsapi::{JSObject, JSContext};
 use js::rust::Compartment;
 use netsurfcss::util::VoidPtrLike;
-use servo_util::tree::{TreeNode, TreeNodeRef, TreeUtils};
+use servo_util::tree::{TreeNode, TreeNodeRef};
 
 //
 // The basic Node structure
@@ -177,41 +176,39 @@ impl<View> Clone for AbstractNode<View> {
     }
 }
 
-impl<View> TreeNode<AbstractNode<View>> for Node<View> {
-    fn parent_node(&self) -> Option<AbstractNode<View>> {
-        self.parent_node
-    }
-    fn first_child(&self) -> Option<AbstractNode<View>> {
-        self.first_child
-    }
-    fn last_child(&self) -> Option<AbstractNode<View>> {
-        self.last_child
-    }
-    fn prev_sibling(&self) -> Option<AbstractNode<View>> {
-        self.prev_sibling
-    }
-    fn next_sibling(&self) -> Option<AbstractNode<View>> {
-        self.next_sibling
-    }
-
-    fn set_parent_node(&mut self, new_parent_node: Option<AbstractNode<View>>) {
-        self.parent_node = new_parent_node
-    }
-    fn set_first_child(&mut self, new_first_child: Option<AbstractNode<View>>) {
-        self.first_child = new_first_child
-    }
-    fn set_last_child(&mut self, new_last_child: Option<AbstractNode<View>>) {
-        self.last_child = new_last_child
-    }
-    fn set_prev_sibling(&mut self, new_prev_sibling: Option<AbstractNode<View>>) {
-        self.prev_sibling = new_prev_sibling
-    }
-    fn set_next_sibling(&mut self, new_next_sibling: Option<AbstractNode<View>>) {
-        self.next_sibling = new_next_sibling
-    }
-}
-
 impl<View> TreeNodeRef<Node<View>> for AbstractNode<View> {
+    fn parent_node(node: &Node<View>) -> Option<AbstractNode<View>> {
+        node.parent_node
+    }
+    fn first_child(node: &Node<View>) -> Option<AbstractNode<View>> {
+        node.first_child
+    }
+    fn last_child(node: &Node<View>) -> Option<AbstractNode<View>> {
+        node.last_child
+    }
+    fn prev_sibling(node: &Node<View>) -> Option<AbstractNode<View>> {
+        node.prev_sibling
+    }
+    fn next_sibling(node: &Node<View>) -> Option<AbstractNode<View>> {
+        node.next_sibling
+    }
+
+    fn set_parent_node(node: &mut Node<View>, new_parent_node: Option<AbstractNode<View>>) {
+        node.parent_node = new_parent_node
+    }
+    fn set_first_child(node: &mut Node<View>, new_first_child: Option<AbstractNode<View>>) {
+        node.first_child = new_first_child
+    }
+    fn set_last_child(node: &mut Node<View>, new_last_child: Option<AbstractNode<View>>) {
+        node.last_child = new_last_child
+    }
+    fn set_prev_sibling(node: &mut Node<View>, new_prev_sibling: Option<AbstractNode<View>>) {
+        node.prev_sibling = new_prev_sibling
+    }
+    fn set_next_sibling(node: &mut Node<View>, new_next_sibling: Option<AbstractNode<View>>) {
+        node.next_sibling = new_next_sibling
+    }
+
     // FIXME: The duplication between `with_base` and `with_mut_base` is ugly.
     fn with_base<R>(&self, callback: &fn(&Node<View>) -> R) -> R {
         self.transmute(callback)
@@ -222,6 +219,8 @@ impl<View> TreeNodeRef<Node<View>> for AbstractNode<View> {
     }
 }
 
+impl<View> TreeNode<AbstractNode<View>> for Node<View> { }
+
 impl<'self, View> AbstractNode<View> {
     // Unsafe accessors
 
@@ -250,7 +249,7 @@ impl<'self, View> AbstractNode<View> {
     /// allowed to call this. This is wildly unsafe and is therefore marked as such.
     pub unsafe fn unsafe_layout_data<T>(self) -> @mut T {
         do self.with_base |base| {
-            transmute(base.layout_data.get())
+            transmute(base.layout_data.unwrap())
         }
     }
     /// Returns true if this node has layout data and false otherwise.
@@ -438,7 +437,7 @@ impl<'self, View> AbstractNode<View> {
     /// Dumps the node tree, for debugging, with indentation.
     pub fn dump_indent(&self, indent: uint) {
         let mut s = ~"";
-        for uint::range(0u, indent) |_i| {
+        for _ in range(0, indent) {
             s.push_str("    ");
         }
 
@@ -446,7 +445,7 @@ impl<'self, View> AbstractNode<View> {
         debug!("%s", s);
 
         // FIXME: this should have a pure version?
-        for self.each_child() |kid| {
+        for kid in self.children() {
             kid.dump_indent(indent + 1u)
         }
     }
@@ -464,7 +463,7 @@ impl<'self, View> AbstractNode<View> {
 }
 
 impl<View> Iterator<AbstractNode<View>> for AbstractNodeChildrenIterator<View> {
-    pub fn next(&mut self) -> Option<AbstractNode<View>> {
+    fn next(&mut self) -> Option<AbstractNode<View>> {
         let node = self.current_node;
         self.current_node = self.current_node.chain(|node| node.next_sibling());
         node
@@ -483,14 +482,14 @@ impl Node<ScriptView> {
 
     pub fn add_to_doc(&mut self, doc: AbstractDocument) {
         self.owner_doc = Some(doc);
-        let mut node = self.first_child;
-        while node.is_some() {
-            for node.get().traverse_preorder |node| {
+        let mut cur_node = self.first_child;
+        while cur_node.is_some() {
+            for node in cur_node.unwrap().traverse_preorder() {
                 do node.with_mut_base |node_base| {
                     node_base.owner_doc = Some(doc);
                 }
             };
-            node = node.get().next_sibling();
+            cur_node = cur_node.unwrap().next_sibling();
         }
     }
 
diff --git a/src/components/script/dom/window.rs b/src/components/script/dom/window.rs
index 3f8339f913d..38f7901eafb 100644
--- a/src/components/script/dom/window.rs
+++ b/src/components/script/dom/window.rs
@@ -18,13 +18,13 @@ use js::{JSVAL_NULL, JSPROP_ENUMERATE};
 
 use std::cast;
 use std::comm;
-use std::comm::Chan;
-use std::int;
+use std::comm::SharedChan;
 use std::io;
 use std::ptr;
+use std::int;
+use std::rt::rtio::RtioTimer;
+use std::rt::io::timer::Timer;
 use js::jsapi::JSVal;
-use extra::timer;
-use extra::uv_global_loop;
 
 pub enum TimerControlMsg {
     TimerMessage_Fire(~TimerData),
@@ -38,7 +38,7 @@ pub struct Window {
     script_chan: ScriptChan,
     compositor: @ScriptListener,
     wrapper: WrapperCache,
-    timer_chan: Chan<TimerControlMsg>,
+    timer_chan: SharedChan<TimerControlMsg>,
 }
 
 #[unsafe_destructor]
@@ -68,7 +68,7 @@ impl Window {
 
     pub fn Document(&self) -> AbstractDocument {
         unsafe {
-            (*self.page).frame.get().document
+            (*self.page).frame.unwrap().document
         }
     }
 
@@ -142,18 +142,19 @@ impl BindingObject for Window {
 
 impl Window {
     pub fn SetTimeout(&self, _cx: *JSContext, callback: JSVal, timeout: i32) -> i32 {
-        let timeout = int::max(0, timeout) as uint;
+        let timeout = int::max(0, timeout) as u64;
 
         // Post a delayed message to the per-window timer task; it will dispatch it
         // to the relevant script handler that will deal with it.
-        let data = ~TimerData {
-            funval: callback,
-            args: ~[]
-        };
-        timer::delayed_send(&uv_global_loop::get(),
-                            timeout,
-                            &self.timer_chan,
-                            TimerMessage_Fire(data));
+        let tm = Timer::new().unwrap();
+        let chan = self.timer_chan.clone();
+        do spawn {
+            tm.sleep(timeout);
+            chan.send(TimerMessage_Fire(~TimerData {
+                funval: callback,
+                args: ~[]
+            }));
+        }
         return 0; //TODO return handle into list of active timers
     }
 
@@ -182,7 +183,7 @@ impl Window {
                         }
                     }
                 }
-                timer_chan
+                SharedChan::new(timer_chan)
             },
         };
 
diff --git a/src/components/script/html/cssparse.rs b/src/components/script/html/cssparse.rs
index 95a600682ac..6d9d0d18a5a 100644
--- a/src/components/script/html/cssparse.rs
+++ b/src/components/script/html/cssparse.rs
@@ -11,7 +11,7 @@ use std::task;
 use newcss::stylesheet::Stylesheet;
 use newcss::util::DataStream;
 use servo_net::resource_task::{ResourceTask, ProgressMsg, Load, Payload, Done};
-use extra::net::url::Url;
+use extra::url::Url;
 
 /// Where a style sheet comes from.
 pub enum StylesheetProvenance {
@@ -28,8 +28,8 @@ pub fn spawn_css_parser(provenance: StylesheetProvenance,
     do task::spawn {
         let url = do provenance_cell.with_ref |p| {
             match *p {
-                UrlProvenance(ref the_url) => copy *the_url,
-                InlineProvenance(ref the_url, _) => copy *the_url
+                UrlProvenance(ref the_url) => (*the_url).clone(),
+                InlineProvenance(ref the_url, _) => (*the_url).clone()
             }
         };
 
diff --git a/src/components/script/html/hubbub_html_parser.rs b/src/components/script/html/hubbub_html_parser.rs
index fd89d71da96..1aad6dc007c 100644
--- a/src/components/script/html/hubbub_html_parser.rs
+++ b/src/components/script/html/hubbub_html_parser.rs
@@ -54,19 +54,18 @@ use newcss::stylesheet::Stylesheet;
 use std::cast;
 use std::cell::Cell;
 use std::comm;
-use std::comm::{Chan, Port, SharedChan};
+use std::comm::{Port, SharedChan};
 use std::str::eq_slice;
-use std::result;
 use std::task;
+use std::from_str::FromStr;
 use hubbub::hubbub;
 use servo_msg::constellation_msg::SubpageId;
 use servo_net::image_cache_task::ImageCacheTask;
 use servo_net::image_cache_task;
 use servo_net::resource_task::{Done, Load, Payload, ResourceTask};
-use servo_util::tree::TreeUtils;
+use servo_util::tree::TreeNodeRef;
 use servo_util::url::make_url;
-use extra::net::url::Url;
-use extra::net::url;
+use extra::url::Url;
 use extra::future::{Future, from_port};
 use geom::size::Size2D;
 
@@ -167,7 +166,7 @@ fn css_link_listener(to_parent: SharedChan<HtmlDiscoveryMessage>,
 
     // Send the sheets back in order
     // FIXME: Shouldn't wait until after we've recieved CSSTaskExit to start sending these
-    for result_vec.iter().advance |port| {
+    for port in result_vec.iter() {
         to_parent.send(HtmlDiscoveredStyle(port.recv()));
     }
 }
@@ -185,7 +184,7 @@ fn js_script_listener(to_parent: SharedChan<HtmlDiscoveryMessage>,
                 do task::spawn {
                     let (input_port, input_chan) = comm::stream();
                     // TODO: change copy to move once we can move into closures
-                    resource_task.send(Load(copy url, input_chan));
+                    resource_task.send(Load(url.clone(), input_chan));
 
                     let mut buf = ~[];
                     loop {
@@ -273,7 +272,6 @@ fn build_element_from_tag(cx: *JSContext, tag: &str) -> AbstractNode<ScriptView>
     }
 }
 
-#[allow(non_implicitly_copyable_typarams)]
 pub fn parse_html(cx: *JSContext,
                   url: Url,
                   resource_task: ResourceTask,
@@ -348,7 +346,7 @@ pub fn parse_html(cx: *JSContext,
 
             debug!("-- attach attrs");
             do node.as_mut_element |element| {
-                for tag.attributes.iter().advance |attr| {
+                for attr in tag.attributes.iter() {
                     element.set_attr(&str(attr.name.clone()), &str(attr.value.clone()));
                 }
             }
@@ -377,7 +375,7 @@ pub fn parse_html(cx: *JSContext,
                         let iframe_chan = iframe_chan.take();
                         let elem = &mut iframe_element.parent.parent;
                         let src_opt = elem.get_attr("src").map(|x| x.to_str());
-                        for src_opt.iter().advance |src| {
+                        for src in src_opt.iter() {
                             let iframe_url = make_url(src.clone(), Some(url2.clone()));
                             iframe_element.frame = Some(iframe_url.clone());
                             
@@ -404,7 +402,7 @@ pub fn parse_html(cx: *JSContext,
                             None => {}
                             Some(src) => {
                                 let img_url = make_url(src, Some(url2.clone()));
-                                image_element.image = Some(copy img_url);
+                                image_element.image = Some(img_url.clone());
                                 // inform the image cache to load this, but don't store a handle.
                                 // TODO (Issue #84): don't prefetch if we are within a <noscript>
                                 // tag.
@@ -475,7 +473,6 @@ pub fn parse_html(cx: *JSContext,
         },
         complete_script: |script| {
             // A little function for holding this lint attr
-            #[allow(non_implicitly_copyable_typarams)]
             fn complete_script(script: hubbub::NodeDataPtr,
                                url: Url,
                                js_chan: SharedChan<JSMessage>) {
@@ -500,12 +497,12 @@ pub fn parse_html(cx: *JSContext,
             // We've reached the end of a <style> so we can submit all the text to the parser.
             unsafe {
                 let style: AbstractNode<ScriptView> = NodeWrapping::from_hubbub_node(style);
-                let url = url::from_str("http://example.com/"); // FIXME
+                let url = FromStr::from_str("http://example.com/"); // FIXME
                 let url_cell = Cell::new(url);
 
                 let mut data = ~[];
                 debug!("iterating over children %?", style.first_child());
-                for style.children().advance |child| {
+                for child in style.children() {
                     debug!("child = %?", child);
                     do child.with_imm_text() |text| {
                         data.push(text.parent.data.to_str());  // FIXME: Bad copy.
@@ -513,7 +510,7 @@ pub fn parse_html(cx: *JSContext,
                 }
 
                 debug!("data = %?", data);
-                let provenance = InlineProvenance(result::unwrap(url_cell.take()), data.concat());
+                let provenance = InlineProvenance(url_cell.take().unwrap(), data.concat());
                 css_chan3.send(CSSTaskNewFile(provenance));
             }
         },
diff --git a/src/components/script/layout_interface.rs b/src/components/script/layout_interface.rs
index 9c9f27328c6..b9e349bf50e 100644
--- a/src/components/script/layout_interface.rs
+++ b/src/components/script/layout_interface.rs
@@ -14,7 +14,7 @@ use geom::size::Size2D;
 use geom::point::Point2D;
 use gfx::geometry::Au;
 use newcss::stylesheet::Stylesheet;
-use extra::net::url::Url;
+use extra::url::Url;
 
 /// Asynchronous messages that script can send to layout.
 ///
@@ -62,7 +62,7 @@ impl DocumentDamageLevel {
     ///
     /// FIXME(pcwalton): This could be refactored to use `max` and the `Ord` trait, and this
     /// function removed.
-    fn add(&mut self, new_damage: DocumentDamageLevel) {
+    pub fn add(&mut self, new_damage: DocumentDamageLevel) {
         match (*self, new_damage) {
             (ReflowDocumentDamage, new_damage) => *self = new_damage,
             (MatchSelectorsDocumentDamage, _) => *self = MatchSelectorsDocumentDamage,
diff --git a/src/components/script/script_task.rs b/src/components/script/script_task.rs
index 3386f058b08..28249044e7d 100644
--- a/src/components/script/script_task.rs
+++ b/src/components/script/script_task.rs
@@ -25,11 +25,9 @@ use servo_msg::constellation_msg::{PipelineId, SubpageId, RendererReadyMsg, Resi
 use servo_msg::constellation_msg::{LoadIframeUrlMsg};
 use servo_msg::constellation_msg;
 
-use newcss::stylesheet::Stylesheet;
-
 use std::cell::Cell;
 use std::comm;
-use std::comm::{Port, SharedChan, Select2};
+use std::comm::{Port, SharedChan};
 use std::io::read_whole_file;
 use std::ptr::null;
 use std::task::{SingleThreaded, task};
@@ -50,8 +48,7 @@ use servo_net::image_cache_task::ImageCacheTask;
 use servo_net::resource_task::ResourceTask;
 use servo_util::tree::TreeNodeRef;
 use servo_util::url::make_url;
-use extra::net::url::Url;
-use extra::net::url;
+use extra::url::Url;
 use extra::future::{from_value, Future};
 
 /// Messages used to control the script task.
@@ -162,7 +159,7 @@ impl PageTree {
 
     pub fn find<'a> (&'a mut self, id: PipelineId) -> Option<&'a mut PageTree> {
         if self.page.id == id { return Some(self); }
-        for self.inner.mut_iter().advance |page_tree| {
+        for page_tree in self.inner.mut_iter() {
             let found = page_tree.find(id);
             if found.is_some() { return found; }
         }
@@ -181,7 +178,7 @@ impl<'self> Iterator<@mut Page> for PageTreeIterator<'self> {
         if !self.stack.is_empty() {
             let next = self.stack.pop();
             {
-                for next.inner.mut_iter().advance |child| {
+                for child in next.inner.mut_iter() {
                     self.stack.push(child);
                 }
             }
@@ -266,7 +263,7 @@ impl Page {
                 // Send new document and relevant styles to layout.
                 let reflow = ~Reflow {
                     document_root: do frame.document.with_base |doc| { doc.root },
-                    url: copy self.url.get_ref().first(),
+                    url: self.url.get_ref().first().clone(),
                     goal: goal,
                     window_size: self.window_size.get(),
                     script_chan: script_chan,
@@ -485,20 +482,20 @@ impl ScriptTask {
 
     /// Handles a request to execute a script.
     fn handle_execute_msg(&mut self, id: PipelineId, url: Url) {
-        debug!("script: Received url `%s` to execute", url::to_str(&url));
+        debug!("script: Received url `%s` to execute", url.to_str());
 
         let page_tree = self.page_tree.find(id).expect("ScriptTask: received fire timer msg for a
             pipeline ID not associated with this script task. This is a bug.");
         let js_info = page_tree.page.js_info.get_ref();
 
         match read_whole_file(&Path(url.path)) {
-            Err(msg) => println(fmt!("Error opening %s: %s", url::to_str(&url), msg)),
+            Err(msg) => println(fmt!("Error opening %s: %s", url.to_str(), msg)),
 
             Ok(bytes) => {
                 js_info.js_compartment.define_functions(debug_fns);
                 js_info.js_context.evaluate_script(js_info.js_compartment.global_obj,
                                                    bytes,
-                                                   copy url.path,
+                                                   url.path.clone(),
                                                    1);
             }
         }
@@ -549,16 +546,16 @@ impl ScriptTask {
     fn handle_resize_inactive_msg(&mut self, new_size: Size2D<uint>) {
         self.page_tree.page.window_size = from_value(new_size);
         let last_loaded_url = replace(&mut self.page_tree.page.url, None);
-        for last_loaded_url.iter().advance |last_loaded_url| {
-            self.page_tree.page.url = Some((last_loaded_url.first(), true));
+        for url in last_loaded_url.iter() {
+            self.page_tree.page.url = Some((url.first(), true));
         }
     }
 
     /// Handles a request to exit the script task and shut down layout.
     fn handle_exit_msg(&mut self) {
-        for self.page_tree.iter().advance |page| {
+        for page in self.page_tree.iter() {
             page.join_layout();
-            do page.frame.get().document.with_mut_base |doc| {
+            do page.frame.unwrap().document.with_mut_base |doc| {
                 doc.teardown();
             }
             page.layout_chan.send(layout_interface::ExitMsg);
@@ -574,10 +571,10 @@ impl ScriptTask {
             message for a layout channel that is not associated with this script task. This
             is a bug.").page;
         let last_loaded_url = replace(&mut page.url, None);
-        for last_loaded_url.iter().advance |last_loaded_url| {
-            let (ref last_loaded_url, needs_reflow) = *last_loaded_url;
-            if *last_loaded_url == url {
-                page.url = Some((last_loaded_url.clone(), false));
+        for loaded in last_loaded_url.iter() {
+            let (ref loaded, needs_reflow) = *loaded;
+            if *loaded == url {
+                page.url = Some((loaded.clone(), false));
                 if needs_reflow {
                     page.reflow_all(ReflowForDisplay, self.chan.clone(), self.compositor);
                 }
@@ -661,7 +658,7 @@ impl ScriptTask {
 
         // Receive the JavaScript scripts.
         assert!(js_scripts.is_some());
-        let js_scripts = js_scripts.swap_unwrap();
+        let js_scripts = js_scripts.take_unwrap();
         debug!("js_scripts: %?", js_scripts);
 
         // Perform the initial reflow.
@@ -677,7 +674,7 @@ impl ScriptTask {
         js_info.js_compartment.define_functions(debug_fns);
 
         // Evaluate every script in the document.
-        for js_scripts.iter().advance |bytes| {
+        for bytes in js_scripts.iter() {
             let _ = js_info.js_context.evaluate_script(js_info.js_compartment.global_obj,
                                                        bytes.clone(),
                                                        ~"???",
@@ -757,10 +754,10 @@ impl ScriptTask {
         }
     }
 
-    priv fn load_url_from_element(&self, page: @mut Page, element: &Element) {
+    fn load_url_from_element(&self, page: @mut Page, element: &Element) {
         // if the node's element is "a," load url from href attr
-        let href = element.get_attr("href");
-        for href.iter().advance |href| {
+        let attr = element.get_attr("href");
+        for href in attr.iter() {
             debug!("ScriptTask: clicked on link to %s", *href);
             let current_url = do page.url.map |&(ref url, _)| {
                 url.clone()
diff --git a/src/components/util/range.rs b/src/components/util/range.rs
index 72719a97f8d..6f3ce3e9e86 100644
--- a/src/components/util/range.rs
+++ b/src/components/util/range.rs
@@ -2,8 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use std::uint;
 use std::cmp::{max, min};
+use std::iterator;
 
 enum RangeRelation {
     OverlapsBegin(/* overlap */ uint),
@@ -15,6 +15,7 @@ enum RangeRelation {
     EntirelyAfter
 }
 
+#[deriving(Clone)]
 pub struct Range {
     priv off: uint,
     priv len: uint
@@ -35,13 +36,8 @@ impl Range {
     pub fn length(&self) -> uint { self.len }
     pub fn end(&self) -> uint { self.off + self.len }
 
-    pub fn eachi(&self, callback: &fn(uint) -> bool) -> bool {
-        for uint::range(self.off, self.off + self.len) |i| {
-            if !callback(i) {
-                break
-            }
-        }
-        true
+    pub fn eachi(&self) -> iterator::Range<uint> {
+        range(self.off, self.off + self.len)
     }
 
     pub fn contains(&self, i: uint) -> bool {
diff --git a/src/components/util/time.rs b/src/components/util/time.rs
index db3963da08b..cfdb037c4f0 100644
--- a/src/components/util/time.rs
+++ b/src/components/util/time.rs
@@ -26,7 +26,7 @@ impl ProfilerChan {
     }
 }
 
-#[deriving(Eq)]
+#[deriving(Eq, Clone)]
 pub enum ProfilerCategory {
     CompositingCategory,
     LayoutQueryCategory,
@@ -70,7 +70,7 @@ impl ProfilerCategory {
 
     // enumeration of all ProfilerCategory types
     // TODO(tkuehn): is there a better way to ensure proper order of categories?
-    priv fn empty_buckets() -> ProfilerBuckets {
+    fn empty_buckets() -> ProfilerBuckets {
         let buckets = [
             (CompositingCategory, ~[]),
             (LayoutQueryCategory, ~[]),
@@ -92,8 +92,8 @@ impl ProfilerCategory {
     }
 
     // ensure that the order of the buckets matches the order of the enum categories
-    priv fn check_order(vec: &ProfilerBuckets) {
-        for vec.iter().advance |&(category, _)| {
+    fn check_order(vec: &ProfilerBuckets) {
+        for &(category, _) in vec.iter() {
             if category != vec[category as uint].first() {
                 fail!("Enum category does not match bucket index. This is a bug.");
             }
@@ -136,7 +136,7 @@ impl Profiler {
         }
     }
 
-    priv fn handle_msg(&mut self, msg: ProfilerMsg) {
+    fn handle_msg(&mut self, msg: ProfilerMsg) {
         match msg {
             TimeMsg(category, t) => match self.buckets[category as uint] {
                 //TODO(tkuehn): would be nice to have tuple.second_mut()
@@ -151,11 +151,11 @@ impl Profiler {
         self.last_msg = Some(msg);
     }
 
-    priv fn print_buckets(&mut self) {
+    fn print_buckets(&mut self) {
         println(fmt!("%31s %15s %15s %15s %15s %15s",
                          "_category_", "_mean (ms)_", "_median (ms)_",
                          "_min (ms)_", "_max (ms)_", "_bucket size_"));
-        for self.buckets.mut_iter().advance |bucket| {
+        for bucket in self.buckets.mut_iter() {
             let (category, data) = match *bucket {
                 (category, ref mut data) => (category, data),
             };
@@ -163,7 +163,7 @@ impl Profiler {
             let data_len = data.len();
             if data_len > 0 {
                 let (mean, median, &min, &max) =
-                    (data.iter().transform(|&x|x).sum() / (data_len as float),
+                    (data.iter().map(|&x|x).sum() / (data_len as float),
                      data[data_len / 2],
                      data.iter().min().unwrap(),
                      data.iter().max().unwrap());
diff --git a/src/components/util/tree.rs b/src/components/util/tree.rs
index eebf91fa10f..3664bae9ac1 100644
--- a/src/components/util/tree.rs
+++ b/src/components/util/tree.rs
@@ -4,204 +4,293 @@
 
 //! Helper functions for garbage collected doubly-linked trees.
 
-/// The basic trait. This function is meant to encapsulate a clonable reference to a tree node.
-pub trait TreeNodeRef<N> : Clone {
+// Macros to make add_child etc. less painful to write.
+// Code outside this module should instead implement TreeNode
+// and use its default methods.
+macro_rules! get(
+    ($node:expr, $fun:ident) => (
+        TreeNodeRef::$fun::<Node,Self>($node)
+    )
+)
+
+macro_rules! set(
+    ($node:expr, $fun:ident, $val:expr) => (
+        TreeNodeRef::$fun::<Node,Self>($node, $val)
+    )
+)
+
+pub struct ChildIterator<Ref> {
+    priv current: Option<Ref>,
+}
+
+impl<Node, Ref: TreeNodeRef<Node>> Iterator<Ref> for ChildIterator<Ref> {
+    fn next(&mut self) -> Option<Ref> {
+        if self.current.is_none() {
+            return None;
+        }
+
+        // FIXME: Do we need two clones here?
+        let x = self.current.get_ref().clone();
+        self.current = x.with_base(|n| TreeNodeRef::next_sibling::<Node, Ref>(n));
+        Some(x.clone())
+    }
+}
+
+// FIXME: Do this without precomputing a vector of refs.
+// Easy for preorder; harder for postorder.
+pub struct TreeIterator<Ref> {
+    priv nodes: ~[Ref],
+    priv index: uint,
+}
+
+impl<Ref> TreeIterator<Ref> {
+    fn new(nodes: ~[Ref]) -> TreeIterator<Ref> {
+        TreeIterator {
+            nodes: nodes,
+            index: 0,
+        }
+    }
+}
+
+impl<Ref: Clone> Iterator<Ref> for TreeIterator<Ref> {
+    fn next(&mut self) -> Option<Ref> {
+        if self.index >= self.nodes.len() {
+            None
+        } else {
+            let v = self.nodes[self.index].clone();
+            self.index += 1;
+            Some(v)
+        }
+    }
+}
+
+/// A type implementing TreeNodeRef<Node> is a clonable reference to an underlying
+/// node type Node.
+///
+/// We have to define both ref and node operations in the same trait, which makes
+/// the latter more annoying to call (as static methods).  But we provide non-static
+/// proxies in trait TreeNode below.
+pub trait TreeNodeRef<Node>: Clone {
+
+    // Fundamental operations on refs.
+
     /// Borrows this node as immutable.
-    fn with_base<R>(&self, callback: &fn(&N) -> R) -> R;
+    fn with_base<R>(&self, callback: &fn(&Node) -> R) -> R;
 
     /// Borrows this node as mutable.
-    fn with_mut_base<R>(&self, callback: &fn(&mut N) -> R) -> R;
-}
+    fn with_mut_base<R>(&self, callback: &fn(&mut Node) -> R) -> R;
+
+
+    // Fundamental operations on nodes.
 
-/// The contents of a tree node.
-pub trait TreeNode<NR> {
     /// Returns the parent of this node.
-    fn parent_node(&self) -> Option<NR>;
+    fn parent_node(node: &Node) -> Option<Self>;
 
     /// Returns the first child of this node.
-    fn first_child(&self) -> Option<NR>;
+    fn first_child(node: &Node) -> Option<Self>;
 
     /// Returns the last child of this node.
-    fn last_child(&self) -> Option<NR>;
+    fn last_child(node: &Node) -> Option<Self>;
 
     /// Returns the previous sibling of this node.
-    fn prev_sibling(&self) -> Option<NR>;
+    fn prev_sibling(node: &Node) -> Option<Self>;
 
     /// Returns the next sibling of this node.
-    fn next_sibling(&self) -> Option<NR>;
+    fn next_sibling(node: &Node) -> Option<Self>;
 
     /// Sets the parent of this node.
-    fn set_parent_node(&mut self, new_parent: Option<NR>);
+    fn set_parent_node(node: &mut Node, new_parent: Option<Self>);
 
     /// Sets the first child of this node.
-    fn set_first_child(&mut self, new_first_child: Option<NR>);
+    fn set_first_child(node: &mut Node, new_first_child: Option<Self>);
 
     /// Sets the last child of this node.
-    fn set_last_child(&mut self, new_last_child: Option<NR>);
+    fn set_last_child(node: &mut Node, new_last_child: Option<Self>);
 
     /// Sets the previous sibling of this node.
-    fn set_prev_sibling(&mut self, new_prev_sibling: Option<NR>);
+    fn set_prev_sibling(node: &mut Node, new_prev_sibling: Option<Self>);
 
     /// Sets the next sibling of this node.
-    fn set_next_sibling(&mut self, new_next_sibling: Option<NR>);
-}
+    fn set_next_sibling(node: &mut Node, new_next_sibling: Option<Self>);
+
+
+    // The tree utilities, operating on refs mostly.
 
-/// A set of helper functions useful for operating on trees.
-pub trait TreeUtils {
     /// Returns true if this node is disconnected from the tree or has no children.
-    fn is_leaf(&self) -> bool;
+    fn is_leaf(&self) -> bool {
+        do self.with_base |this_node| {
+            (get!(this_node, first_child)).is_none()
+        }
+    }
 
     /// Adds a new child to the end of this node's list of children.
     ///
     /// Fails unless `new_child` is disconnected from the tree.
-    fn add_child(&self, new_child: Self);
+    fn add_child(&self, new_child: Self) {
+        do self.with_mut_base |this_node| {
+            do new_child.with_mut_base |new_child_node| {
+                assert!((get!(new_child_node, parent_node)).is_none());
+                assert!((get!(new_child_node, prev_sibling)).is_none());
+                assert!((get!(new_child_node, next_sibling)).is_none());
+
+                match get!(this_node, last_child) {
+                    None => set!(this_node, set_first_child, Some(new_child.clone())),
+                    Some(last_child) => {
+                        do last_child.with_mut_base |last_child_node| {
+                            assert!((get!(last_child_node, next_sibling)).is_none());
+                            set!(last_child_node, set_next_sibling, Some(new_child.clone()));
+                            set!(new_child_node, set_prev_sibling, Some(last_child.clone()));
+                        }
+                    }
+                }
+
+                set!(this_node, set_last_child, Some(new_child.clone()));
+                set!(new_child_node, set_parent_node, Some((*self).clone()));
+            }
+        }
+    }
 
     /// Removes the given child from this node's list of children.
     ///
     /// Fails unless `child` is a child of this node. (FIXME: This is not yet checked.)
-    fn remove_child(&self, child: Self);
+    fn remove_child(&self, child: Self) {
+        do self.with_mut_base |this_node| {
+            do child.with_mut_base |child_node| {
+                assert!((get!(child_node, parent_node)).is_some());
+
+                match get!(child_node, prev_sibling) {
+                    None => set!(this_node, set_first_child, get!(child_node, next_sibling)),
+                    Some(prev_sibling) => {
+                        do prev_sibling.with_mut_base |prev_sibling_node| {
+                            set!(prev_sibling_node, set_next_sibling, get!(child_node, next_sibling));
+                        }
+                    }
+                }
+
+                match get!(child_node, next_sibling) {
+                    None => set!(this_node, set_last_child, get!(child_node, prev_sibling)),
+                    Some(next_sibling) => {
+                        do next_sibling.with_mut_base |next_sibling_node| {
+                            set!(next_sibling_node, set_prev_sibling, get!(child_node, prev_sibling));
+                        }
+                    }
+                }
+
+                set!(child_node, set_prev_sibling, None);
+                set!(child_node, set_next_sibling, None);
+                set!(child_node, set_parent_node,  None);
+            }
+        }
+    }
 
     /// Iterates over all children of this node.
-    fn each_child(&self, callback: &fn(Self) -> bool) -> bool;
+    fn children(&self) -> ChildIterator<Self> {
+        ChildIterator {
+            current: self.with_base(|n| get!(n, first_child)),
+        }
+    }
 
     /// Iterates over this node and all its descendants, in preorder.
-    fn traverse_preorder(&self, callback: &fn(Self) -> bool) -> bool;
+    fn traverse_preorder(&self) -> TreeIterator<Self> {
+        self.traverse_preorder_prune(|_| false)
+    }
 
     /// Iterates over this node and all its descendants, in postorder.
-    fn traverse_postorder(&self, callback: &fn(Self) -> bool) -> bool;
+    fn traverse_postorder(&self) -> TreeIterator<Self> {
+        self.traverse_postorder_prune(|_| false)
+    }
 
     /// Like traverse_preorder but calls 'prune' first on each node.  If it returns true then we
     /// skip the whole subtree but continue iterating.
-    ///
-    /// 'prune' is a separate function a) for compatibility with the 'for' protocol,
-    /// b) so that the postorder version can still prune before traversing.
-    fn traverse_preorder_prune(&self, prune: &fn(&Self) -> bool, callback: &fn(Self) -> bool) -> bool;
+    fn traverse_preorder_prune(&self, prune: &fn(&Self) -> bool) -> TreeIterator<Self> {
+        let mut nodes = ~[];
+        gather(self, &mut nodes, false, prune);
+        TreeIterator::new(nodes)
+    }
 
     /// Like traverse_postorder but calls 'prune' first on each node.  If it returns true then we
     /// skip the whole subtree but continue iterating.
     ///
     /// NB: 'prune' is called *before* traversing children, even though this is a
     /// postorder traversal.
-    fn traverse_postorder_prune(&self, prune: &fn(&Self) -> bool, callback: &fn(Self) -> bool) -> bool;
-}
-
-impl<NR:TreeNodeRef<N>,N:TreeNode<NR>> TreeUtils for NR {
-    fn is_leaf(&self) -> bool {
-        do self.with_base |this_node| {
-            this_node.first_child().is_none()
-        }
-    }
-
-    fn add_child(&self, new_child: NR) {
-        do self.with_mut_base |this_node| {
-            do new_child.with_mut_base |new_child_node| {
-                assert!(new_child_node.parent_node().is_none());
-                assert!(new_child_node.prev_sibling().is_none());
-                assert!(new_child_node.next_sibling().is_none());
-
-                match this_node.last_child() {
-                    None => this_node.set_first_child(Some(new_child.clone())),
-                    Some(last_child) => {
-                        do last_child.with_mut_base |last_child_node| {
-                            assert!(last_child_node.next_sibling().is_none());
-                            last_child_node.set_next_sibling(Some(new_child.clone()));
-                            new_child_node.set_prev_sibling(Some(last_child.clone()));
-                        }
-                    }
-                }
-
-                this_node.set_last_child(Some(new_child.clone()));
-                new_child_node.set_parent_node(Some((*self).clone()));
-            }
-        }
-    }
-
-    fn remove_child(&self, child: NR) {
-        do self.with_mut_base |this_node| {
-            do child.with_mut_base |child_node| {
-                assert!(child_node.parent_node().is_some());
-
-                match child_node.prev_sibling() {
-                    None => this_node.set_first_child(child_node.next_sibling()),
-                    Some(prev_sibling) => {
-                        do prev_sibling.with_mut_base |prev_sibling_node| {
-                            prev_sibling_node.set_next_sibling(child_node.next_sibling());
-                        }
-                    }
-                }
-
-                match child_node.next_sibling() {
-                    None => this_node.set_last_child(child_node.prev_sibling()),
-                    Some(next_sibling) => {
-                        do next_sibling.with_mut_base |next_sibling_node| {
-                            next_sibling_node.set_prev_sibling(child_node.prev_sibling());
-                        }
-                    }
-                }
-
-                child_node.set_prev_sibling(None);
-                child_node.set_next_sibling(None);
-                child_node.set_parent_node(None);
-            }
-        }
-    }
-
-    fn each_child(&self, callback: &fn(NR) -> bool) -> bool {
-        let mut maybe_current = self.with_base(|n| n.first_child());
-        while !maybe_current.is_none() {
-            let current = maybe_current.get_ref().clone();
-            if !callback(current.clone()) {
-                break;
-            }
-
-            maybe_current = current.with_base(|n| n.next_sibling());
-        }
-
-        true
-    }
-
-    fn traverse_preorder_prune(&self, prune: &fn(&NR) -> bool, callback: &fn(NR) -> bool) -> bool {
-        // prune shouldn't mutate, so don't clone
-        if prune(self) {
-            return true;
-        }
-
-        if !callback((*self).clone()) {
-            return false;
-        }
-
-        for self.each_child |kid| {
-            // FIXME: Work around rust#2202. We should be able to pass the callback directly.
-            if !kid.traverse_preorder_prune(|a| prune(a), |a| callback(a)) {
-                return false;
-            }
-        }
-
-        true
-    }
-
-    fn traverse_postorder_prune(&self, prune: &fn(&NR) -> bool, callback: &fn(NR) -> bool) -> bool {
-        // prune shouldn't mutate, so don't clone
-        if prune(self) {
-            return true;
-        }
-
-        for self.each_child |kid| {
-            // FIXME: Work around rust#2202. We should be able to pass the callback directly.
-            if !kid.traverse_postorder_prune(|a| prune(a), |a| callback(a)) {
-                return false;
-            }
-        }
-
-        callback((*self).clone())
-    }
-
-    fn traverse_preorder(&self, callback: &fn(NR) -> bool) -> bool {
-        self.traverse_preorder_prune(|_| false, callback)
-    }
-
-    fn traverse_postorder(&self, callback: &fn(NR) -> bool) -> bool {
-        self.traverse_postorder_prune(|_| false, callback)
+    fn traverse_postorder_prune(&self, prune: &fn(&Self) -> bool) -> TreeIterator<Self> {
+        let mut nodes = ~[];
+        gather(self, &mut nodes, true, prune);
+        TreeIterator::new(nodes)
     }
 }
 
+fn gather<Node, Ref: TreeNodeRef<Node>>(cur: &Ref, refs: &mut ~[Ref],
+                                        postorder: bool, prune: &fn(&Ref) -> bool) {
+    // prune shouldn't mutate, so don't clone
+    if prune(cur) {
+        return;
+    }
+
+    if !postorder {
+        refs.push(cur.clone());
+    }
+    for kid in cur.children() {
+        // FIXME: Work around rust#2202. We should be able to pass the callback directly.
+        gather(&kid, refs, postorder, |a| prune(a))
+    }
+    if postorder {
+        refs.push(cur.clone());
+    }
+}
+
+
+/// Access the fields of a node without a static TreeNodeRef method call.
+/// If you make an impl TreeNodeRef<Node> for Ref then you should also make
+/// impl TreeNode<Ref> for Node with an empty body.
+pub trait TreeNode<Ref: TreeNodeRef<Self>> {
+    /// Returns the parent of this node.
+    fn parent_node(&self) -> Option<Ref> {
+        TreeNodeRef::parent_node::<Self,Ref>(self)
+    }
+
+    /// Returns the first child of this node.
+    fn first_child(&self) -> Option<Ref> {
+        TreeNodeRef::first_child::<Self,Ref>(self)
+    }
+
+    /// Returns the last child of this node.
+    fn last_child(&self) -> Option<Ref> {
+        TreeNodeRef::last_child::<Self,Ref>(self)
+    }
+
+    /// Returns the previous sibling of this node.
+    fn prev_sibling(&self) -> Option<Ref> {
+        TreeNodeRef::prev_sibling::<Self,Ref>(self)
+    }
+
+    /// Returns the next sibling of this node.
+    fn next_sibling(&self) -> Option<Ref> {
+        TreeNodeRef::next_sibling::<Self,Ref>(self)
+    }
+
+    /// Sets the parent of this node.
+    fn set_parent_node(&mut self, new_parent: Option<Ref>) {
+        TreeNodeRef::set_parent_node::<Self,Ref>(self, new_parent)
+    }
+
+    /// Sets the first child of this node.
+    fn set_first_child(&mut self, new_first_child: Option<Ref>) {
+        TreeNodeRef::set_first_child::<Self,Ref>(self, new_first_child)
+    }
+
+    /// Sets the last child of this node.
+    fn set_last_child(&mut self, new_last_child: Option<Ref>) {
+        TreeNodeRef::set_last_child::<Self,Ref>(self, new_last_child)
+    }
+
+    /// Sets the previous sibling of this node.
+    fn set_prev_sibling(&mut self, new_prev_sibling: Option<Ref>) {
+        TreeNodeRef::set_prev_sibling::<Self,Ref>(self, new_prev_sibling)
+    }
+
+    /// Sets the next sibling of this node.
+    fn set_next_sibling(&mut self, new_next_sibling: Option<Ref>) {
+        TreeNodeRef::set_next_sibling::<Self,Ref>(self, new_next_sibling)
+    }
+}
diff --git a/src/components/util/url.rs b/src/components/util/url.rs
index 0cb8a32c3ce..bdfef004335 100644
--- a/src/components/util/url.rs
+++ b/src/components/util/url.rs
@@ -2,11 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use extra::net::url;
-use extra::net::url::Url;
+use extra::url;
+use extra::url::Url;
 use std::hashmap::HashMap;
 use std::os;
-use std::result;
 
 /**
 Create a URL object from a string. Does various helpful browsery things like
@@ -17,10 +16,9 @@ Create a URL object from a string. Does various helpful browsery things like
   is based off the current url
 
 */
-#[allow(non_implicitly_copyable_typarams)]
 pub fn make_url(str_url: ~str, current_url: Option<Url>) -> Url {
     let schm = url::get_scheme(str_url);
-    let str_url = if result::is_err(&schm) {
+    let str_url = if schm.is_err() {
         if current_url.is_none() {
             // Assume we've been given a file path. If it's absolute just return
             // it, otherwise make it absolute with the cwd.
@@ -30,7 +28,7 @@ pub fn make_url(str_url: ~str, current_url: Option<Url>) -> Url {
                 ~"file://" + os::getcwd().push(str_url).to_str()
             }
         } else {
-            let current_url = current_url.get();
+            let current_url = current_url.unwrap();
             debug!("make_url: current_url: %?", current_url);
             if str_url.starts_with("//") {
                 current_url.scheme + ":" + str_url
@@ -41,11 +39,11 @@ pub fn make_url(str_url: ~str, current_url: Option<Url>) -> Url {
                 str_url.trim_left_chars(&'/')
             } else {
                 let mut path = ~[];
-                for current_url.path.split_iter('/').advance |p| {
+                for p in current_url.path.split_iter('/') {
                     path.push(p.to_str());
                 }
                 let path = path.init();
-                let mut path = path.iter().transform(|x| copy *x).collect::<~[~str]>();
+                let mut path = path.iter().map(|x| (*x).clone()).collect::<~[~str]>();
                 path.push(str_url);
                 let path = path.connect("/");
 
@@ -57,7 +55,7 @@ pub fn make_url(str_url: ~str, current_url: Option<Url>) -> Url {
     };
 
     // FIXME: Need to handle errors
-    url::from_str(str_url).get()
+    url::from_str(str_url).unwrap()
 }
 
 mod make_url_tests {
@@ -119,6 +117,6 @@ mod make_url_tests {
 
 pub type UrlMap<T> = @mut HashMap<Url, T>;
 
-pub fn url_map<T: Copy>() -> UrlMap<T> {
+pub fn url_map<T: Clone + 'static>() -> UrlMap<T> {
     @mut HashMap::new()
 }
diff --git a/src/platform/linux/rust-fontconfig b/src/platform/linux/rust-fontconfig
index 78f84af79eb..af20d6eea6e 160000
--- a/src/platform/linux/rust-fontconfig
+++ b/src/platform/linux/rust-fontconfig
@@ -1 +1 @@
-Subproject commit 78f84af79eb653fde2d50621fc3631043fa6fa9e
+Subproject commit af20d6eea6eb4efe31f7f883e8d7073b2bd692a1
diff --git a/src/platform/linux/rust-freetype b/src/platform/linux/rust-freetype
index 980254dd840..9621863ca31 160000
--- a/src/platform/linux/rust-freetype
+++ b/src/platform/linux/rust-freetype
@@ -1 +1 @@
-Subproject commit 980254dd840772c8ee5f37056e7bd9f4d93d5377
+Subproject commit 9621863ca3147412e78782122873d316b8a0f73d
diff --git a/src/platform/linux/rust-xlib b/src/platform/linux/rust-xlib
index 641af36389a..4e8043abbf1 160000
--- a/src/platform/linux/rust-xlib
+++ b/src/platform/linux/rust-xlib
@@ -1 +1 @@
-Subproject commit 641af36389a7592ef0faea2488ec08bd144e9bfe
+Subproject commit 4e8043abbf103805fd6bb3708e111a4220d4280b
diff --git a/src/platform/macos/rust-cocoa b/src/platform/macos/rust-cocoa
index 23bb1728984..25495d9a80f 160000
--- a/src/platform/macos/rust-cocoa
+++ b/src/platform/macos/rust-cocoa
@@ -1 +1 @@
-Subproject commit 23bb17289846dd9486f633c0b5187c7ba333d943
+Subproject commit 25495d9a80f11fdde4fa3cc6bcb3c0ea7462e0bb
diff --git a/src/platform/macos/rust-core-foundation b/src/platform/macos/rust-core-foundation
index 77e9ed24ca7..c5dafee99ad 160000
--- a/src/platform/macos/rust-core-foundation
+++ b/src/platform/macos/rust-core-foundation
@@ -1 +1 @@
-Subproject commit 77e9ed24ca7bb0f9a0b33d7fd888de2905dddcd4
+Subproject commit c5dafee99adea0a31acea07dce09d4f81271a14a
diff --git a/src/platform/macos/rust-core-graphics b/src/platform/macos/rust-core-graphics
index bf9d0ebf3e0..479bccc6f32 160000
--- a/src/platform/macos/rust-core-graphics
+++ b/src/platform/macos/rust-core-graphics
@@ -1 +1 @@
-Subproject commit bf9d0ebf3e0283f8bdb505d29d93de9631f7877c
+Subproject commit 479bccc6f323bc698856f3dc5a9ab93f4ffc8958
diff --git a/src/platform/macos/rust-core-text b/src/platform/macos/rust-core-text
index 313e26f9202..d0c3681561e 160000
--- a/src/platform/macos/rust-core-text
+++ b/src/platform/macos/rust-core-text
@@ -1 +1 @@
-Subproject commit 313e26f9202b44d09043485671bc903786c328e7
+Subproject commit d0c3681561eb83b85773207e44bd2c22aa8445d2
diff --git a/src/platform/macos/rust-io-surface b/src/platform/macos/rust-io-surface
index f155846fe04..0679efa35b6 160000
--- a/src/platform/macos/rust-io-surface
+++ b/src/platform/macos/rust-io-surface
@@ -1 +1 @@
-Subproject commit f155846fe043f9060fa05be696c203180e7371f7
+Subproject commit 0679efa35b682863d25ac19fdb520c35f9a364a5
diff --git a/src/support/alert/rust-alert b/src/support/alert/rust-alert
index 68875af396c..c3a603bb641 160000
--- a/src/support/alert/rust-alert
+++ b/src/support/alert/rust-alert
@@ -1 +1 @@
-Subproject commit 68875af396cb583e670dd5caad99431dac62f8db
+Subproject commit c3a603bb641539bb2b7f3c159fd8ea3de045db8f
diff --git a/src/support/azure/rust-azure b/src/support/azure/rust-azure
index c6774cb3ebd..44aec67e955 160000
--- a/src/support/azure/rust-azure
+++ b/src/support/azure/rust-azure
@@ -1 +1 @@
-Subproject commit c6774cb3ebdb20b1736fa3e8b5e8348fefbc987f
+Subproject commit 44aec67e955dbbd7a56fa19f1e1705653a1a5dd6
diff --git a/src/support/css/rust-css b/src/support/css/rust-css
index 789c7a43e28..9ed02f7f0c4 160000
--- a/src/support/css/rust-css
+++ b/src/support/css/rust-css
@@ -1 +1 @@
-Subproject commit 789c7a43e28629ea0b568ce7d9a7ca8a0a975d34
+Subproject commit 9ed02f7f0c4b704adb3ae60426bbc1b124e1a995
diff --git a/src/support/css/rust-cssparser b/src/support/css/rust-cssparser
index 3dc9f508b85..77921ee3f24 160000
--- a/src/support/css/rust-cssparser
+++ b/src/support/css/rust-cssparser
@@ -1 +1 @@
-Subproject commit 3dc9f508b8517e4efddffb4703e3a5e9d63d4f25
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index 86c9525ec4a..2fdf1f166a7 160000
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