diff --git a/components/util/cache.rs b/components/util/cache.rs
index b3f2aaf55c4..757a6d60c20 100644
--- a/components/util/cache.rs
+++ b/components/util/cache.rs
@@ -59,7 +59,7 @@ impl<K, V> HashCache<K,V>
 
 #[test]
 fn test_hashcache() {
-    let mut cache: HashCache<uint, Cell<&str>> = HashCache::new();
+    let mut cache: HashCache<usize, Cell<&str>> = HashCache::new();
 
     cache.insert(1, Cell::new("one"));
     assert!(cache.find(&1).is_some());
@@ -72,11 +72,11 @@ fn test_hashcache() {
 
 pub struct LRUCache<K, V> {
     entries: Vec<(K, V)>,
-    cache_size: uint,
+    cache_size: usize,
 }
 
 impl<K: Clone + PartialEq, V: Clone> LRUCache<K,V> {
-    pub fn new(size: uint) -> LRUCache<K, V> {
+    pub fn new(size: usize) -> LRUCache<K, V> {
         LRUCache {
           entries: vec!(),
           cache_size: size,
@@ -84,7 +84,7 @@ impl<K: Clone + PartialEq, V: Clone> LRUCache<K,V> {
     }
 
     #[inline]
-    pub fn touch(&mut self, pos: uint) -> V {
+    pub fn touch(&mut self, pos: usize) -> V {
         let last_index = self.entries.len() - 1;
         if pos != last_index {
             let entry = self.entries.remove(pos);
@@ -134,7 +134,7 @@ pub struct SimpleHashCache<K,V> {
 }
 
 impl<K:Clone+Eq+Hash<SipHasher>,V:Clone> SimpleHashCache<K,V> {
-    pub fn new(cache_size: uint) -> SimpleHashCache<K,V> {
+    pub fn new(cache_size: usize) -> SimpleHashCache<K,V> {
         let mut r = rand::thread_rng();
         SimpleHashCache {
             entries: repeat(None).take(cache_size).collect(),
@@ -144,15 +144,15 @@ impl<K:Clone+Eq+Hash<SipHasher>,V:Clone> SimpleHashCache<K,V> {
     }
 
     #[inline]
-    fn to_bucket(&self, h: uint) -> uint {
+    fn to_bucket(&self, h: usize) -> usize {
         h % self.entries.len()
     }
 
     #[inline]
-    fn bucket_for_key<Q:Hash<SipHasher>>(&self, key: &Q) -> uint {
+    fn bucket_for_key<Q:Hash<SipHasher>>(&self, key: &Q) -> usize {
         let mut hasher = SipHasher::new_with_keys(self.k0, self.k1);
         key.hash(&mut hasher);
-        self.to_bucket(hasher.finish() as uint)
+        self.to_bucket(hasher.finish() as usize)
     }
 
     pub fn insert(&mut self, key: K, value: V) {
diff --git a/components/util/debug_utils.rs b/components/util/debug_utils.rs
index 8d9789de029..f7c02b8068b 100644
--- a/components/util/debug_utils.rs
+++ b/components/util/debug_utils.rs
@@ -12,7 +12,7 @@ fn hexdump_slice(buf: &[u8]) {
     let mut stderr = io::stderr();
     stderr.write_all(b"    ").unwrap();
     for (i, &v) in buf.iter().enumerate() {
-        let output = format!("{:02X} ", v as uint);
+        let output = format!("{:02X} ", v);
         stderr.write_all(output.as_bytes()).unwrap();
         match i % 16 {
             15 => { stderr.write_all(b"\n    ").unwrap(); },
diff --git a/components/util/deque/mod.rs b/components/util/deque/mod.rs
index 6dce728679b..089edf6bd43 100644
--- a/components/util/deque/mod.rs
+++ b/components/util/deque/mod.rs
@@ -57,23 +57,23 @@ use std::mem::{forget, min_align_of, size_of, transmute};
 use std::ptr;
 
 use std::sync::Mutex;
-use std::sync::atomic::{AtomicInt, AtomicPtr};
+use std::sync::atomic::{AtomicIsize, AtomicPtr};
 use std::sync::atomic::Ordering::SeqCst;
 
 // Once the queue is less than 1/K full, then it will be downsized. Note that
 // the deque requires that this number be less than 2.
-static K: int = 4;
+static K: isize = 4;
 
 // Minimum number of bits that a buffer size should be. No buffer will resize to
 // under this value, and all deques will initially contain a buffer of this
 // size.
 //
 // The size in question is 1 << MIN_BITS
-static MIN_BITS: uint = 7;
+static MIN_BITS: usize = 7;
 
 struct Deque<T> {
-    bottom: AtomicInt,
-    top: AtomicInt,
+    bottom: AtomicIsize,
+    top: AtomicIsize,
     array: AtomicPtr<Buffer<T>>,
     pool: BufferPool<T>,
 }
@@ -139,7 +139,7 @@ pub struct BufferPool<T> {
 ///      LLVM is probably pretty good at doing this already.
 struct Buffer<T> {
     storage: *const T,
-    log_size: uint,
+    log_size: usize,
 }
 
 unsafe impl<T: 'static> Send for Buffer<T> { }
@@ -159,7 +159,7 @@ impl<T: Send> BufferPool<T> {
         (Worker { deque: a }, Stealer { deque: b })
     }
 
-    fn alloc(&mut self, bits: uint) -> Box<Buffer<T>> {
+    fn alloc(&mut self, bits: usize) -> Box<Buffer<T>> {
         unsafe {
             let mut pool = self.pool.lock().unwrap();
             match pool.iter().position(|x| x.size() >= (1 << bits)) {
@@ -228,8 +228,8 @@ impl<T: Send> Deque<T> {
     fn new(mut pool: BufferPool<T>) -> Deque<T> {
         let buf = pool.alloc(MIN_BITS);
         Deque {
-            bottom: AtomicInt::new(0),
-            top: AtomicInt::new(0),
+            bottom: AtomicIsize::new(0),
+            top: AtomicIsize::new(0),
             array: AtomicPtr::new(unsafe { transmute(buf) }),
             pool: pool,
         }
@@ -299,7 +299,7 @@ impl<T: Send> Deque<T> {
         }
     }
 
-    unsafe fn maybe_shrink(&self, b: int, t: int) {
+    unsafe fn maybe_shrink(&self, b: isize, t: isize) {
         let a = self.array.load(SeqCst);
         if b - t < (*a).size() / K && b - t > (1 << MIN_BITS) {
             self.swap_buffer(b, a, (*a).resize(b, t, -1));
@@ -313,7 +313,7 @@ impl<T: Send> Deque<T> {
     // after this method has called 'free' on it. The continued usage is simply
     // a read followed by a forget, but we must make sure that the memory can
     // continue to be read after we flag this buffer for reclamation.
-    unsafe fn swap_buffer(&self, b: int, old: *mut Buffer<T>,
+    unsafe fn swap_buffer(&self, b: isize, old: *mut Buffer<T>,
                           buf: Buffer<T>) -> *mut Buffer<T> {
         let newbuf: *mut Buffer<T> = transmute(box buf);
         self.array.store(newbuf, SeqCst);
@@ -345,12 +345,12 @@ impl<T: Send> Drop for Deque<T> {
 }
 
 #[inline]
-fn buffer_alloc_size<T>(log_size: uint) -> uint {
+fn buffer_alloc_size<T>(log_size: usize) -> usize {
     (1 << log_size) * size_of::<T>()
 }
 
 impl<T: Send> Buffer<T> {
-    unsafe fn new(log_size: uint) -> Buffer<T> {
+    unsafe fn new(log_size: usize) -> Buffer<T> {
         let size = buffer_alloc_size::<T>(log_size);
         let buffer = allocate(size, min_align_of::<T>());
         if buffer.is_null() { ::alloc::oom() }
@@ -360,12 +360,12 @@ impl<T: Send> Buffer<T> {
         }
     }
 
-    fn size(&self) -> int { 1 << self.log_size }
+    fn size(&self) -> isize { 1 << self.log_size }
 
     // Apparently LLVM cannot optimize (foo % (1 << bar)) into this implicitly
-    fn mask(&self) -> int { (1 << self.log_size) - 1 }
+    fn mask(&self) -> isize { (1 << self.log_size) - 1 }
 
-    unsafe fn elem(&self, i: int) -> *const T {
+    unsafe fn elem(&self, i: isize) -> *const T {
         self.storage.offset(i & self.mask())
     }
 
@@ -373,23 +373,23 @@ impl<T: Send> Buffer<T> {
     // nor does this clear out the contents contained within. Hence, this is a
     // very unsafe method which the caller needs to treat specially in case a
     // race is lost.
-    unsafe fn get(&self, i: int) -> T {
+    unsafe fn get(&self, i: isize) -> T {
         ptr::read(self.elem(i))
     }
 
     // Unsafe because this unsafely overwrites possibly uninitialized or
     // initialized data.
-    unsafe fn put(&self, i: int, t: T) {
+    unsafe fn put(&self, i: isize, t: T) {
         ptr::write(self.elem(i) as *mut T, t);
     }
 
     // Again, unsafe because this has incredibly dubious ownership violations.
     // It is assumed that this buffer is immediately dropped.
-    unsafe fn resize(&self, b: int, t: int, delta: int) -> Buffer<T> {
+    unsafe fn resize(&self, b: isize, t: isize, delta: isize) -> Buffer<T> {
         // NB: not entirely obvious, but thanks to 2's complement,
-        // casting delta to uint and then adding gives the desired
+        // casting delta to usize and then adding gives the desired
         // effect.
-        let buf = Buffer::new(self.log_size + delta as uint);
+        let buf = Buffer::new(self.log_size + delta as usize);
         for i in range(t, b) {
             buf.put(i, self.get(i));
         }
diff --git a/components/util/geometry.rs b/components/util/geometry.rs
index 59f61c5afc0..3a165facb5c 100644
--- a/components/util/geometry.rs
+++ b/components/util/geometry.rs
@@ -236,7 +236,7 @@ impl Au {
     }
 
     #[inline]
-    pub fn from_px(px: int) -> Au {
+    pub fn from_px(px: isize) -> Au {
         NumCast::from(px * 60).unwrap()
     }
 
@@ -246,9 +246,9 @@ impl Au {
     }
 
     #[inline]
-    pub fn to_nearest_px(&self) -> int {
+    pub fn to_nearest_px(&self) -> isize {
         let Au(s) = *self;
-        ((s as f64) / 60f64).round() as int
+        ((s as f64) / 60f64).round() as isize
     }
 
     #[inline]
@@ -309,13 +309,13 @@ pub fn from_frac_px(px: f64) -> Au {
     Au((px * 60f64) as i32)
 }
 
-pub fn from_px(px: int) -> Au {
+pub fn from_px(px: isize) -> Au {
     NumCast::from(px * 60).unwrap()
 }
 
-pub fn to_px(au: Au) -> int {
+pub fn to_px(au: Au) -> isize {
     let Au(a) = au;
-    (a / 60) as int
+    (a / 60) as isize
 }
 
 pub fn to_frac_px(au: Au) -> f64 {
@@ -325,7 +325,7 @@ pub fn to_frac_px(au: Au) -> f64 {
 
 // assumes 72 points per inch, and 96 px per inch
 pub fn from_pt(pt: f64) -> Au {
-    from_px((pt / 72f64 * 96f64) as int)
+    from_px((pt / 72f64 * 96f64) as isize)
 }
 
 // assumes 72 points per inch, and 96 px per inch
diff --git a/components/util/memory.rs b/components/util/memory.rs
index f895c129fea..e5e20d4cc94 100644
--- a/components/util/memory.rs
+++ b/components/util/memory.rs
@@ -241,7 +241,7 @@ macro_rules! option_try(
 );
 
 #[cfg(target_os="linux")]
-fn get_proc_self_statm_field(field: uint) -> Option<u64> {
+fn get_proc_self_statm_field(field: usize) -> Option<u64> {
     let mut f = File::open(&Path::new("/proc/self/statm"));
     match f.read_to_string() {
         Ok(contents) => {
diff --git a/components/util/opts.rs b/components/util/opts.rs
index b64fe4e8f46..6bcbf694940 100644
--- a/components/util/opts.rs
+++ b/components/util/opts.rs
@@ -28,14 +28,14 @@ pub struct Opts {
     /// How many threads to use for CPU painting (`-t`).
     ///
     /// Note that painting is sequentialized when using GPU painting.
-    pub paint_threads: uint,
+    pub paint_threads: usize,
 
     /// True to use GPU painting via Skia-GL, false to use CPU painting via Skia (`-g`). Note that
     /// compositing is always done on the GPU.
     pub gpu_painting: bool,
 
     /// The maximum size of each tile in pixels (`-s`).
-    pub tile_size: uint,
+    pub tile_size: usize,
 
     /// The ratio of device pixels per px at the default scale. If unspecified, will use the
     /// platform default setting.
@@ -54,7 +54,7 @@ pub struct Opts {
 
     /// The number of threads to use for layout (`-y`). Defaults to 1, which results in a recursive
     /// sequential algorithm.
-    pub layout_threads: uint,
+    pub layout_threads: usize,
 
     pub nonincremental_layout: bool,
 
@@ -102,7 +102,7 @@ pub struct Opts {
     pub devtools_port: Option<u16>,
 
     /// The initial requested size of the window.
-    pub initial_window_size: TypedSize2D<ScreenPx, uint>,
+    pub initial_window_size: TypedSize2D<ScreenPx, u32>,
 
     /// An optional string allowing the user agent to be set for testing.
     pub user_agent: Option<String>,
@@ -256,7 +256,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
         opt_match.free.clone()
     };
 
-    let tile_size: uint = match opt_match.opt_str("s") {
+    let tile_size: usize = match opt_match.opt_str("s") {
         Some(tile_size_str) => tile_size_str.parse().unwrap(),
         None => 512,
     };
@@ -265,7 +265,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
         ScaleFactor(dppx_str.parse().unwrap())
     );
 
-    let mut paint_threads: uint = match opt_match.opt_str("t") {
+    let mut paint_threads: usize = match opt_match.opt_str("t") {
         Some(paint_threads_str) => paint_threads_str.parse().unwrap(),
         None => cmp::max(rt::default_sched_threads() * 3 / 4, 1),
     };
@@ -280,7 +280,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
 
     let gpu_painting = !FORCE_CPU_PAINTING && opt_match.opt_present("g");
 
-    let mut layout_threads: uint = match opt_match.opt_str("y") {
+    let mut layout_threads: usize = match opt_match.opt_str("y") {
         Some(layout_threads_str) => layout_threads_str.parse().unwrap(),
         None => cmp::max(rt::default_sched_threads() * 3 / 4, 1),
     };
@@ -301,7 +301,7 @@ pub fn from_cmdline_args(args: &[String]) -> bool {
 
     let initial_window_size = match opt_match.opt_str("resolution") {
         Some(res_string) => {
-            let res: Vec<uint> = res_string.split('x').map(|r| r.parse().unwrap()).collect();
+            let res: Vec<u32> = res_string.split('x').map(|r| r.parse().unwrap()).collect();
             TypedSize2D(res[0], res[1])
         }
         None => {
diff --git a/components/util/persistent_list.rs b/components/util/persistent_list.rs
index f20edff3d38..e78dc3daa1e 100644
--- a/components/util/persistent_list.rs
+++ b/components/util/persistent_list.rs
@@ -9,7 +9,7 @@ use std::sync::Arc;
 
 pub struct PersistentList<T> {
     head: PersistentListLink<T>,
-    length: uint,
+    length: usize,
 }
 
 struct PersistentListEntry<T> {
@@ -29,7 +29,7 @@ impl<T> PersistentList<T> where T: Send + Sync {
     }
 
     #[inline]
-    pub fn len(&self) -> uint {
+    pub fn len(&self) -> usize {
         self.length
     }
 
diff --git a/components/util/taskpool.rs b/components/util/taskpool.rs
index 5572395fc98..d3f52c5018b 100644
--- a/components/util/taskpool.rs
+++ b/components/util/taskpool.rs
@@ -25,7 +25,7 @@ pub struct TaskPool {
 }
 
 impl TaskPool {
-    pub fn new(tasks: uint) -> TaskPool {
+    pub fn new(tasks: u32) -> TaskPool {
         assert!(tasks > 0);
         let (tx, rx) = channel();
 
diff --git a/components/util/tid.rs b/components/util/tid.rs
index 7351f85f085..9a01a19f6ce 100644
--- a/components/util/tid.rs
+++ b/components/util/tid.rs
@@ -8,10 +8,10 @@ use std::cell::RefCell;
 
 static mut next_tid: AtomicUsize = ATOMIC_USIZE_INIT;
 
-thread_local!(static TASK_LOCAL_TID: Rc<RefCell<Option<uint>>> = Rc::new(RefCell::new(None)));
+thread_local!(static TASK_LOCAL_TID: Rc<RefCell<Option<usize>>> = Rc::new(RefCell::new(None)));
 
 /// Every task gets one, that's unique.
-pub fn tid() -> uint {
+pub fn tid() -> usize {
     TASK_LOCAL_TID.with(|ref k| {
         let ret =
             match *k.borrow() {
diff --git a/components/util/vec.rs b/components/util/vec.rs
index 960e7e8db1a..a1b07126e06 100644
--- a/components/util/vec.rs
+++ b/components/util/vec.rs
@@ -16,11 +16,11 @@ pub trait Comparator<K,T> {
 
 pub trait BinarySearchMethods<'a, T: Ord + PartialOrd + PartialEq> {
     fn binary_search_(&self, key: &T) -> Option<&'a T>;
-    fn binary_search_index(&self, key: &T) -> Option<uint>;
+    fn binary_search_index(&self, key: &T) -> Option<usize>;
 }
 
 pub trait FullBinarySearchMethods<T> {
-    fn binary_search_index_by<K,C:Comparator<K,T>>(&self, key: &K, cmp: C) -> Option<uint>;
+    fn binary_search_index_by<K,C:Comparator<K,T>>(&self, key: &K, cmp: C) -> Option<usize>;
 }
 
 impl<'a, T: Ord + PartialOrd + PartialEq> BinarySearchMethods<'a, T> for &'a [T] {
@@ -28,28 +28,28 @@ impl<'a, T: Ord + PartialOrd + PartialEq> BinarySearchMethods<'a, T> for &'a [T]
         self.binary_search_index(key).map(|i| &self[i])
     }
 
-    fn binary_search_index(&self, key: &T) -> Option<uint> {
+    fn binary_search_index(&self, key: &T) -> Option<usize> {
         self.binary_search_index_by(key, DefaultComparator)
     }
 }
 
 impl<'a, T> FullBinarySearchMethods<T> for &'a [T] {
-    fn binary_search_index_by<K,C:Comparator<K,T>>(&self, key: &K, cmp: C) -> Option<uint> {
+    fn binary_search_index_by<K,C:Comparator<K,T>>(&self, key: &K, cmp: C) -> Option<usize> {
         if self.len() == 0 {
             return None;
         }
 
-        let mut low : int = 0;
-        let mut high : int = (self.len() as int) - 1;
+        let mut low : isize = 0;
+        let mut high : isize = (self.len() as isize) - 1;
 
         while low <= high {
             // http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html
-            let mid = ((low as uint) + (high as uint)) >> 1;
+            let mid = ((low as usize) + (high as usize)) >> 1;
             let midv = &self[mid];
 
             match cmp.compare(key, midv) {
-                Ordering::Greater => low = (mid as int) + 1,
-                Ordering::Less => high = (mid as int) - 1,
+                Ordering::Greater => low = (mid as isize) + 1,
+                Ordering::Less => high = (mid as isize) - 1,
                 Ordering::Equal => return Some(mid),
             }
         }
diff --git a/components/util/workqueue.rs b/components/util/workqueue.rs
index ad39b1e349f..c24f40602f9 100644
--- a/components/util/workqueue.rs
+++ b/components/util/workqueue.rs
@@ -13,7 +13,7 @@ use task_state;
 use libc::funcs::posix88::unistd::usleep;
 use std::mem;
 use rand::{Rng, weak_rng, XorShiftRng};
-use std::sync::atomic::{AtomicUint, Ordering};
+use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::mpsc::{channel, Sender, Receiver};
 use deque::{Abort, BufferPool, Data, Empty, Stealer, Worker};
 
@@ -33,7 +33,7 @@ pub struct WorkUnit<QueueData, WorkData> {
 /// Messages from the supervisor to the worker.
 enum WorkerMsg<QueueData: 'static, WorkData: 'static> {
     /// Tells the worker to start work.
-    Start(Worker<WorkUnit<QueueData, WorkData>>, *mut AtomicUint, *const QueueData),
+    Start(Worker<WorkUnit<QueueData, WorkData>>, *mut AtomicUsize, *const QueueData),
     /// Tells the worker to stop. It can be restarted again with a `WorkerMsg::Start`.
     Stop,
     /// Tells the worker thread to terminate.
@@ -45,7 +45,7 @@ unsafe impl<QueueData: 'static, WorkData: 'static> Send for WorkerMsg<QueueData,
 /// Messages to the supervisor.
 enum SupervisorMsg<QueueData: 'static, WorkData: 'static> {
     Finished,
-    ReturnDeque(uint, Worker<WorkUnit<QueueData, WorkData>>),
+    ReturnDeque(usize, Worker<WorkUnit<QueueData, WorkData>>),
 }
 
 unsafe impl<QueueData: 'static, WorkData: 'static> Send for SupervisorMsg<QueueData, WorkData> {}
@@ -63,7 +63,7 @@ struct WorkerInfo<QueueData: 'static, WorkData: 'static> {
 /// Information specific to each worker thread that the thread keeps.
 struct WorkerThread<QueueData: 'static, WorkData: 'static> {
     /// The index of this worker.
-    index: uint,
+    index: usize,
     /// The communication port from the supervisor.
     port: Receiver<WorkerMsg<QueueData, WorkData>>,
     /// The communication channel on which messages are sent to the supervisor.
@@ -110,7 +110,7 @@ impl<QueueData: Send, WorkData: Send> WorkerThread<QueueData, WorkData> {
                         let mut i = 0;
                         let mut should_continue = true;
                         loop {
-                            let victim = (self.rng.next_u32() as uint) % self.other_deques.len();
+                            let victim = (self.rng.next_u32() as usize) % self.other_deques.len();
                             match self.other_deques[victim].steal() {
                                 Empty | Abort => {
                                     // Continue.
@@ -179,7 +179,7 @@ impl<QueueData: Send, WorkData: Send> WorkerThread<QueueData, WorkData> {
 /// A handle to the work queue that individual work units have.
 pub struct WorkerProxy<'a, QueueData: 'a, WorkData: 'a> {
     worker: &'a mut Worker<WorkUnit<QueueData, WorkData>>,
-    ref_count: *mut AtomicUint,
+    ref_count: *mut AtomicUsize,
     queue_data: *const QueueData,
     worker_index: u8,
 }
@@ -216,7 +216,7 @@ pub struct WorkQueue<QueueData: 'static, WorkData: 'static> {
     /// A port on which deques can be received from the workers.
     port: Receiver<SupervisorMsg<QueueData, WorkData>>,
     /// The amount of work that has been enqueued.
-    work_count: uint,
+    work_count: usize,
     /// Arbitrary user data.
     pub data: QueueData,
 }
@@ -226,7 +226,7 @@ impl<QueueData: Send, WorkData: Send> WorkQueue<QueueData, WorkData> {
     /// it.
     pub fn new(task_name: &'static str,
                state: task_state::TaskState,
-               thread_count: uint,
+               thread_count: usize,
                user_data: QueueData) -> WorkQueue<QueueData, WorkData> {
         // Set up data structures.
         let (supervisor_chan, supervisor_port) = channel();
@@ -295,7 +295,7 @@ impl<QueueData: Send, WorkData: Send> WorkQueue<QueueData, WorkData> {
     /// Synchronously runs all the enqueued tasks and waits for them to complete.
     pub fn run(&mut self) {
         // Tell the workers to start.
-        let mut work_count = AtomicUint::new(self.work_count);
+        let mut work_count = AtomicUsize::new(self.work_count);
         for worker in self.workers.iter_mut() {
             worker.chan.send(WorkerMsg::Start(worker.deque.take().unwrap(), &mut work_count, &self.data)).unwrap()
         }