diff --git a/src/servo/dom/base.rs b/src/servo/dom/base.rs
index 93bcd6d73e7..04065a80db4 100644
--- a/src/servo/dom/base.rs
+++ b/src/servo/dom/base.rs
@@ -9,7 +9,7 @@ import util::tree;
 import dvec::{dvec, extensions};
 
 enum NodeData = {
-    tree: tree::fields<Node>,
+    tree: tree::Tree<Node>,
     kind: ~NodeKind,
 };
 
@@ -78,7 +78,7 @@ impl NodeScope for NodeScope {
     }
 }
 
-impl of tree::rd_tree_ops<Node> for NodeScope {
+impl TreeReadMethods of tree::ReadMethods<Node> for NodeScope {
     fn each_child(node: Node, f: fn(Node) -> bool) {
         tree::each_child(self, node, f)
     }
@@ -87,17 +87,17 @@ impl of tree::rd_tree_ops<Node> for NodeScope {
         tree::get_parent(self, node)
     }
 
-    fn with_tree_fields<R>(node: Node, f: fn(tree::fields<Node>) -> R) -> R {
+    fn with_tree_fields<R>(node: Node, f: fn(tree::Tree<Node>) -> R) -> R {
         self.read(node) { |n| f(n.tree) }
     }
 }
 
-impl of tree::wr_tree_ops<Node> for NodeScope {
+impl TreeWriteMethods of tree::WriteMethods<Node> for NodeScope {
     fn add_child(node: Node, child: Node) {
         tree::add_child(self, node, child)
     }
 
-    fn with_tree_fields<R>(node: Node, f: fn(tree::fields<Node>) -> R) -> R {
+    fn with_tree_fields<R>(node: Node, f: fn(tree::Tree<Node>) -> R) -> R {
         self.write(node) { |n| f(n.tree) }
     }
 }
diff --git a/src/servo/layout/base.rs b/src/servo/layout/base.rs
index 13497778385..2d5f03746a2 100644
--- a/src/servo/layout/base.rs
+++ b/src/servo/layout/base.rs
@@ -35,7 +35,7 @@ class appearance {
 }
 
 class Box {
-    let tree: tree::fields<@Box>;
+    let tree: tree::Tree<@Box>;
     let node: Node;
     let kind: BoxKind;
     let mut bounds: Rect<au>;
@@ -55,34 +55,36 @@ enum layout_data = {
     mut box: option<@Box>
 };
 
+// FIXME: This is way too complex! Why do these have to have dummy receivers? --pcw
+
 enum ntree { ntree }
-impl of tree::rd_tree_ops<Node> for ntree {
+impl NodeTreeReadMethods of tree::ReadMethods<Node> for ntree {
     fn each_child(node: Node, f: fn(Node) -> bool) {
         tree::each_child(self, node, f)
     }
 
-    fn with_tree_fields<R>(&&n: Node, f: fn(tree::fields<Node>) -> R) -> R {
+    fn with_tree_fields<R>(&&n: Node, f: fn(tree::Tree<Node>) -> R) -> R {
         n.read { |n| f(n.tree) }
     }
 }
 
 enum btree { btree }
-impl of tree::rd_tree_ops<@Box> for btree {
+impl BoxTreeReadMethods of tree::ReadMethods<@Box> for btree {
     fn each_child(node: @Box, f: fn(&&@Box) -> bool) {
         tree::each_child(self, node, f)
     }
 
-    fn with_tree_fields<R>(&&b: @Box, f: fn(tree::fields<@Box>) -> R) -> R {
+    fn with_tree_fields<R>(&&b: @Box, f: fn(tree::Tree<@Box>) -> R) -> R {
         f(b.tree)
     }
 }
 
-impl of tree::wr_tree_ops<@Box> for btree {
+impl BoxTreeWriteMethods of tree::WriteMethods<@Box> for btree {
     fn add_child(node: @Box, child: @Box) {
         tree::add_child(self, node, child)
     }
 
-    fn with_tree_fields<R>(&&b: @Box, f: fn(tree::fields<@Box>) -> R) -> R {
+    fn with_tree_fields<R>(&&b: @Box, f: fn(tree::Tree<@Box>) -> R) -> R {
         f(b.tree)
     }
 }
@@ -155,7 +157,7 @@ impl NodeMethods for Node {
 #[cfg(test)]
 mod test {
     import dom::base::{Element, ElementData, HTMLDivElement, HTMLImageElement, Node, NodeKind};
-    import dom::base::{NodeScope, wr_tree_ops};
+    import dom::base::{NodeScope, TreeWriteMethods};
     import dom::rcu::Scope;
     import box_builder::{box_builder_methods};
 
diff --git a/src/servo/layout/box_builder.rs b/src/servo/layout/box_builder.rs
index cdb121b8bb1..1678e5075e7 100644
--- a/src/servo/layout/box_builder.rs
+++ b/src/servo/layout/box_builder.rs
@@ -4,8 +4,9 @@ import dom::base::{ElementData, HTMLDivElement, HTMLImageElement, Element, Text,
 import dom::style::{display_type, di_block, di_inline, di_none};
 import dom::rcu::ReaderMethods;
 import gfx::geometry;
-import layout::base::{BlockBox, Box, BoxKind, InlineBox, IntrinsicBox, NodeMethods, TextBox};
-import layout::base::{appearance, btree, ntree, rd_tree_ops, wr_tree_ops};
+import layout::base::{BlockBox, Box, BoxKind, BoxTreeReadMethods, BoxTreeWriteMethods, InlineBox};
+import layout::base::{IntrinsicBox, NodeMethods, NodeTreeReadMethods, TextBox};
+import layout::base::{appearance, btree, ntree};
 import layout::style::style::{style_methods};
 import layout::text::text_box;
 import util::tree;
diff --git a/src/servo/layout/style/matching.rs b/src/servo/layout/style/matching.rs
index 5a0b00fdb57..0554319a622 100644
--- a/src/servo/layout/style/matching.rs
+++ b/src/servo/layout/style/matching.rs
@@ -203,7 +203,7 @@ impl matching_methods for Node {
 
 mod test {
     import dom::base::{Attr, Element, HTMLDivElement, HTMLHeadElement, HTMLImageElement};
-    import dom::base::{NodeScope, UnknownElement, wr_tree_ops};
+    import dom::base::{NodeScope, TreeReadMethods, TreeWriteMethods, UnknownElement};
     import dvec::{dvec, extensions};
     import io::println;
 
diff --git a/src/servo/parser/html_builder.rs b/src/servo/parser/html_builder.rs
index 91163d11555..097012a661e 100644
--- a/src/servo/parser/html_builder.rs
+++ b/src/servo/parser/html_builder.rs
@@ -1,8 +1,8 @@
 #[doc="Constructs a DOM tree from an incoming token stream."]
 
 import dom::base::{Attr, Element, ElementData, ElementKind, HTMLDivElement, HTMLHeadElement};
-import dom::base::{HTMLImageElement, Node, NodeScope, Text, UnknownElement, rd_tree_ops};
-import dom::base::{wr_tree_ops};
+import dom::base::{HTMLImageElement, Node, NodeScope, Text, TreeReadMethods, TreeWriteMethods};
+import dom::base::{UnknownElement};
 import dom::rcu::WriterMethods;
 import geom::size::Size2D;
 import gfx::geometry;
diff --git a/src/servo/util/tree.rs b/src/servo/util/tree.rs
index 38e734c715b..cbb3db09620 100644
--- a/src/servo/util/tree.rs
+++ b/src/servo/util/tree.rs
@@ -2,7 +2,7 @@
 //
 // TODO: Use traits.
 
-type fields<T> = {
+type Tree<T> = {
     mut parent: option<T>,
     mut first_child: option<T>,
     mut last_child: option<T>,
@@ -10,17 +10,15 @@ type fields<T> = {
     mut next_sibling: option<T>
 };
 
-iface rd_tree_ops<T> {
-    fn with_tree_fields<R>(T, f: fn(fields<T>) -> R) -> R;
+iface ReadMethods<T> {
+    fn with_tree_fields<R>(T, f: fn(Tree<T>) -> R) -> R;
 }
 
-iface wr_tree_ops<T> {
-    fn with_tree_fields<R>(T, f: fn(fields<T>) -> R) -> R;
+iface WriteMethods<T> {
+    fn with_tree_fields<R>(T, f: fn(Tree<T>) -> R) -> R;
 }
 
-fn each_child<T:copy,O:rd_tree_ops<T>>(
-    ops: O, node: T, f: fn(T) -> bool) {
-
+fn each_child<T:copy,O:ReadMethods<T>>(ops: O, node: T, f: fn(T) -> bool) {
     let mut p = ops.with_tree_fields(node) { |f| f.first_child };
     loop {
         alt copy p {
@@ -33,7 +31,7 @@ fn each_child<T:copy,O:rd_tree_ops<T>>(
     }
 }
 
-fn empty<T>() -> fields<T> {
+fn empty<T>() -> Tree<T> {
     {mut parent: none,
      mut first_child: none,
      mut last_child: none,
@@ -41,7 +39,7 @@ fn empty<T>() -> fields<T> {
      mut next_sibling: none}
 }
 
-fn add_child<T:copy,O:wr_tree_ops<T>>(
+fn add_child<T:copy,O:WriteMethods<T>>(
     ops: O, parent: T, child: T) {
 
     ops.with_tree_fields(child) { |child_tf|
@@ -73,27 +71,27 @@ fn add_child<T:copy,O:wr_tree_ops<T>>(
     }
 }
 
-fn get_parent<T:copy,O:rd_tree_ops<T>>(ops: O, node: T) -> option<T> {
+fn get_parent<T:copy,O:ReadMethods<T>>(ops: O, node: T) -> option<T> {
     ops.with_tree_fields(node) { |tf| tf.parent }
 }
 
 #[cfg(test)]
 mod test {
     enum dummy = @{
-        fields: fields<dummy>,
+        fields: Tree<dummy>,
         value: uint
     };
 
     enum dtree { dtree }
 
-    impl of rd_tree_ops<dummy> for dtree {
-        fn with_tree_fields<R>(d: dummy, f: fn(fields<dummy>) -> R) -> R {
+    impl of ReadMethods<dummy> for dtree {
+        fn with_tree_fields<R>(d: dummy, f: fn(Tree<dummy>) -> R) -> R {
             f(d.fields)
         }
     }
 
-    impl of wr_tree_ops<dummy> for dtree {
-        fn with_tree_fields<R>(d: dummy, f: fn(fields<dummy>) -> R) -> R {
+    impl of WriteMethods<dummy> for dtree {
+        fn with_tree_fields<R>(d: dummy, f: fn(Tree<dummy>) -> R) -> R {
             f(d.fields)
         }
     }