diff --git a/src/liballoc/arc.rs b/src/liballoc/arc.rs
index 21c47cdf3d752..f6f83f22f9240 100644
--- a/src/liballoc/arc.rs
+++ b/src/liballoc/arc.rs
@@ -458,7 +458,7 @@ impl<T: Sync + Send> Drop for Weak<T> {
     }
 }
 
-#[unstable = "waiting on PartialEq"]
+#[stable]
 impl<T: PartialEq> PartialEq for Arc<T> {
     /// Equality for two `Arc<T>`s.
     ///
@@ -490,7 +490,7 @@ impl<T: PartialEq> PartialEq for Arc<T> {
     /// ```
     fn ne(&self, other: &Arc<T>) -> bool { *(*self) != *(*other) }
 }
-#[unstable = "waiting on PartialOrd"]
+#[stable]
 impl<T: PartialOrd> PartialOrd for Arc<T> {
     /// Partial comparison for two `Arc<T>`s.
     ///
@@ -569,11 +569,11 @@ impl<T: PartialOrd> PartialOrd for Arc<T> {
     /// ```
     fn ge(&self, other: &Arc<T>) -> bool { *(*self) >= *(*other) }
 }
-#[unstable = "waiting on Ord"]
+#[stable]
 impl<T: Ord> Ord for Arc<T> {
     fn cmp(&self, other: &Arc<T>) -> Ordering { (**self).cmp(&**other) }
 }
-#[unstable = "waiting on Eq"]
+#[stable]
 impl<T: Eq> Eq for Arc<T> {}
 
 impl<T: fmt::Show> fmt::Show for Arc<T> {
diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index 3c6b2d2cbc068..74f0599e486e1 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -72,12 +72,14 @@ impl<T: Clone> Clone for Box<T> {
     }
 }
 
+#[stable]
 impl<Sized? T: PartialEq> PartialEq for Box<T> {
     #[inline]
     fn eq(&self, other: &Box<T>) -> bool { PartialEq::eq(&**self, &**other) }
     #[inline]
     fn ne(&self, other: &Box<T>) -> bool { PartialEq::ne(&**self, &**other) }
 }
+#[stable]
 impl<Sized? T: PartialOrd> PartialOrd for Box<T> {
     #[inline]
     fn partial_cmp(&self, other: &Box<T>) -> Option<Ordering> {
@@ -92,12 +94,14 @@ impl<Sized? T: PartialOrd> PartialOrd for Box<T> {
     #[inline]
     fn gt(&self, other: &Box<T>) -> bool { PartialOrd::gt(&**self, &**other) }
 }
+#[stable]
 impl<Sized? T: Ord> Ord for Box<T> {
     #[inline]
     fn cmp(&self, other: &Box<T>) -> Ordering {
         Ord::cmp(&**self, &**other)
     }
-}
+
+#[stable]}
 impl<Sized? T: Eq> Eq for Box<T> {}
 
 impl<S: hash::Writer, Sized? T: Hash<S>> Hash<S> for Box<T> {
diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 214fae02ce272..75d4342083b98 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -452,7 +452,7 @@ impl<T: Default> Default for Rc<T> {
     }
 }
 
-#[unstable = "PartialEq is unstable."]
+#[stable]
 impl<T: PartialEq> PartialEq for Rc<T> {
     /// Equality for two `Rc<T>`s.
     ///
@@ -487,10 +487,10 @@ impl<T: PartialEq> PartialEq for Rc<T> {
     fn ne(&self, other: &Rc<T>) -> bool { **self != **other }
 }
 
-#[unstable = "Eq is unstable."]
+#[stable]
 impl<T: Eq> Eq for Rc<T> {}
 
-#[unstable = "PartialOrd is unstable."]
+#[stable]
 impl<T: PartialOrd> PartialOrd for Rc<T> {
     /// Partial comparison for two `Rc<T>`s.
     ///
@@ -575,7 +575,7 @@ impl<T: PartialOrd> PartialOrd for Rc<T> {
     fn ge(&self, other: &Rc<T>) -> bool { **self >= **other }
 }
 
-#[unstable = "Ord is unstable."]
+#[stable]
 impl<T: Ord> Ord for Rc<T> {
     /// Comparison for two `Rc<T>`s.
     ///
diff --git a/src/libcollections/bit.rs b/src/libcollections/bit.rs
index 430d7210bf69b..08d12151efd3d 100644
--- a/src/libcollections/bit.rs
+++ b/src/libcollections/bit.rs
@@ -965,6 +965,7 @@ impl Clone for Bitv {
     }
 }
 
+#[stable]
 impl PartialOrd for Bitv {
     #[inline]
     fn partial_cmp(&self, other: &Bitv) -> Option<Ordering> {
@@ -972,6 +973,7 @@ impl PartialOrd for Bitv {
     }
 }
 
+#[stable]
 impl Ord for Bitv {
     #[inline]
     fn cmp(&self, other: &Bitv) -> Ordering {
@@ -997,6 +999,7 @@ impl<S: hash::Writer> hash::Hash<S> for Bitv {
     }
 }
 
+#[stable]
 impl cmp::PartialEq for Bitv {
     #[inline]
     fn eq(&self, other: &Bitv) -> bool {
@@ -1007,6 +1010,7 @@ impl cmp::PartialEq for Bitv {
     }
 }
 
+#[stable]
 impl cmp::Eq for Bitv {}
 
 /// An iterator for `Bitv`.
@@ -1129,6 +1133,7 @@ impl Extend<uint> for BitvSet {
     }
 }
 
+#[stable]
 impl PartialOrd for BitvSet {
     #[inline]
     fn partial_cmp(&self, other: &BitvSet) -> Option<Ordering> {
@@ -1137,6 +1142,7 @@ impl PartialOrd for BitvSet {
     }
 }
 
+#[stable]
 impl Ord for BitvSet {
     #[inline]
     fn cmp(&self, other: &BitvSet) -> Ordering {
@@ -1145,6 +1151,7 @@ impl Ord for BitvSet {
     }
 }
 
+#[stable]
 impl cmp::PartialEq for BitvSet {
     #[inline]
     fn eq(&self, other: &BitvSet) -> bool {
@@ -1153,6 +1160,7 @@ impl cmp::PartialEq for BitvSet {
     }
 }
 
+#[stable]
 impl cmp::Eq for BitvSet {}
 
 impl BitvSet {
diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs
index 65c644da3d892..a3dff3e870658 100644
--- a/src/libcollections/btree/map.rs
+++ b/src/libcollections/btree/map.rs
@@ -843,6 +843,7 @@ impl<K: Ord, V> Default for BTreeMap<K, V> {
     }
 }
 
+#[stable]
 impl<K: PartialEq, V: PartialEq> PartialEq for BTreeMap<K, V> {
     fn eq(&self, other: &BTreeMap<K, V>) -> bool {
         self.len() == other.len() &&
@@ -850,8 +851,10 @@ impl<K: PartialEq, V: PartialEq> PartialEq for BTreeMap<K, V> {
     }
 }
 
+#[stable]
 impl<K: Eq, V: Eq> Eq for BTreeMap<K, V> {}
 
+#[stable]
 impl<K: PartialOrd, V: PartialOrd> PartialOrd for BTreeMap<K, V> {
     #[inline]
     fn partial_cmp(&self, other: &BTreeMap<K, V>) -> Option<Ordering> {
@@ -859,6 +862,7 @@ impl<K: PartialOrd, V: PartialOrd> PartialOrd for BTreeMap<K, V> {
     }
 }
 
+#[stable]
 impl<K: Ord, V: Ord> Ord for BTreeMap<K, V> {
     #[inline]
     fn cmp(&self, other: &BTreeMap<K, V>) -> Ordering {
diff --git a/src/libcollections/dlist.rs b/src/libcollections/dlist.rs
index d8ce79f4fe90d..9f2dcda92c025 100644
--- a/src/libcollections/dlist.rs
+++ b/src/libcollections/dlist.rs
@@ -770,6 +770,7 @@ impl<A> Extend<A> for DList<A> {
     }
 }
 
+#[stable]
 impl<A: PartialEq> PartialEq for DList<A> {
     fn eq(&self, other: &DList<A>) -> bool {
         self.len() == other.len() &&
@@ -782,14 +783,17 @@ impl<A: PartialEq> PartialEq for DList<A> {
     }
 }
 
+#[stable]
 impl<A: Eq> Eq for DList<A> {}
 
+#[stable]
 impl<A: PartialOrd> PartialOrd for DList<A> {
     fn partial_cmp(&self, other: &DList<A>) -> Option<Ordering> {
         iter::order::partial_cmp(self.iter(), other.iter())
     }
 }
 
+#[stable]
 impl<A: Ord> Ord for DList<A> {
     #[inline]
     fn cmp(&self, other: &DList<A>) -> Ordering {
diff --git a/src/libcollections/ring_buf.rs b/src/libcollections/ring_buf.rs
index df8e08f07a321..c8d21761ac088 100644
--- a/src/libcollections/ring_buf.rs
+++ b/src/libcollections/ring_buf.rs
@@ -1290,6 +1290,7 @@ impl<'a, T: 'a> DoubleEndedIterator<T> for Drain<'a, T> {
 
 impl<'a, T: 'a> ExactSizeIterator<T> for Drain<'a, T> {}
 
+#[stable]
 impl<A: PartialEq> PartialEq for RingBuf<A> {
     fn eq(&self, other: &RingBuf<A>) -> bool {
         self.len() == other.len() &&
@@ -1297,14 +1298,17 @@ impl<A: PartialEq> PartialEq for RingBuf<A> {
     }
 }
 
+#[stable]
 impl<A: Eq> Eq for RingBuf<A> {}
 
+#[stable]
 impl<A: PartialOrd> PartialOrd for RingBuf<A> {
     fn partial_cmp(&self, other: &RingBuf<A>) -> Option<Ordering> {
         iter::order::partial_cmp(self.iter(), other.iter())
     }
 }
 
+#[stable]
 impl<A: Ord> Ord for RingBuf<A> {
     #[inline]
     fn cmp(&self, other: &RingBuf<A>) -> Ordering {
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index c6c19cae75f1e..0969f0fcfcc47 100644
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -815,6 +815,7 @@ impl<'a> Extend<&'a str> for String {
     }
 }
 
+#[stable]
 impl PartialEq for String {
     #[inline]
     fn eq(&self, other: &String) -> bool { PartialEq::eq(&**self, &**other) }
@@ -824,6 +825,7 @@ impl PartialEq for String {
 
 macro_rules! impl_eq {
     ($lhs:ty, $rhs: ty) => {
+        #[stable]
         impl<'a> PartialEq<$rhs> for $lhs {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool { PartialEq::eq(&**self, &**other) }
@@ -831,6 +833,7 @@ macro_rules! impl_eq {
             fn ne(&self, other: &$rhs) -> bool { PartialEq::ne(&**self, &**other) }
         }
 
+        #[stable]
         impl<'a> PartialEq<$lhs> for $rhs {
             #[inline]
             fn eq(&self, other: &$lhs) -> bool { PartialEq::eq(&**self, &**other) }
@@ -844,6 +847,7 @@ macro_rules! impl_eq {
 impl_eq! { String, &'a str }
 impl_eq! { CowString<'a>, String }
 
+#[stable]
 impl<'a, 'b> PartialEq<&'b str> for CowString<'a> {
     #[inline]
     fn eq(&self, other: &&'b str) -> bool { PartialEq::eq(&**self, &**other) }
@@ -851,6 +855,7 @@ impl<'a, 'b> PartialEq<&'b str> for CowString<'a> {
     fn ne(&self, other: &&'b str) -> bool { PartialEq::ne(&**self, &**other) }
 }
 
+#[stable]
 impl<'a, 'b> PartialEq<CowString<'a>> for &'b str {
     #[inline]
     fn eq(&self, other: &CowString<'a>) -> bool { PartialEq::eq(&**self, &**other) }
diff --git a/src/libcollections/vec.rs b/src/libcollections/vec.rs
index bf69980b49c8f..e2a9d2f8f63c6 100644
--- a/src/libcollections/vec.rs
+++ b/src/libcollections/vec.rs
@@ -588,6 +588,7 @@ impl<T> Extend<T> for Vec<T> {
     }
 }
 
+#[stable]
 impl<A, B> PartialEq<Vec<B>> for Vec<A> where A: PartialEq<B> {
     #[inline]
     fn eq(&self, other: &Vec<B>) -> bool { PartialEq::eq(&**self, &**other) }
@@ -597,6 +598,7 @@ impl<A, B> PartialEq<Vec<B>> for Vec<A> where A: PartialEq<B> {
 
 macro_rules! impl_eq {
     ($lhs:ty, $rhs:ty) => {
+        #[stable]
         impl<'b, A, B> PartialEq<$rhs> for $lhs where A: PartialEq<B> {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool { PartialEq::eq(&**self, &**other) }
@@ -604,6 +606,7 @@ macro_rules! impl_eq {
             fn ne(&self, other: &$rhs) -> bool { PartialEq::ne(&**self, &**other) }
         }
 
+        #[stable]
         impl<'b, A, B> PartialEq<$lhs> for $rhs where B: PartialEq<A> {
             #[inline]
             fn eq(&self, other: &$lhs) -> bool { PartialEq::eq(&**self, &**other) }
@@ -616,6 +619,7 @@ macro_rules! impl_eq {
 impl_eq! { Vec<A>, &'b [B] }
 impl_eq! { Vec<A>, &'b mut [B] }
 
+#[stable]
 impl<'a, A, B> PartialEq<Vec<B>> for CowVec<'a, A> where A: PartialEq<B> + Clone {
     #[inline]
     fn eq(&self, other: &Vec<B>) -> bool { PartialEq::eq(&**self, &**other) }
@@ -623,6 +627,7 @@ impl<'a, A, B> PartialEq<Vec<B>> for CowVec<'a, A> where A: PartialEq<B> + Clone
     fn ne(&self, other: &Vec<B>) -> bool { PartialEq::ne(&**self, &**other) }
 }
 
+#[stable]
 impl<'a, A, B> PartialEq<CowVec<'a, A>> for Vec<B> where A: Clone, B: PartialEq<A> {
     #[inline]
     fn eq(&self, other: &CowVec<'a, A>) -> bool { PartialEq::eq(&**self, &**other) }
@@ -632,6 +637,7 @@ impl<'a, A, B> PartialEq<CowVec<'a, A>> for Vec<B> where A: Clone, B: PartialEq<
 
 macro_rules! impl_eq_for_cowvec {
     ($rhs:ty) => {
+        #[stable]
         impl<'a, 'b, A, B> PartialEq<$rhs> for CowVec<'a, A> where A: PartialEq<B> + Clone {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool { PartialEq::eq(&**self, &**other) }
@@ -639,6 +645,7 @@ macro_rules! impl_eq_for_cowvec {
             fn ne(&self, other: &$rhs) -> bool { PartialEq::ne(&**self, &**other) }
         }
 
+        #[stable]
         impl<'a, 'b, A, B> PartialEq<CowVec<'a, A>> for $rhs where A: Clone, B: PartialEq<A> {
             #[inline]
             fn eq(&self, other: &CowVec<'a, A>) -> bool { PartialEq::eq(&**self, &**other) }
@@ -651,7 +658,7 @@ macro_rules! impl_eq_for_cowvec {
 impl_eq_for_cowvec! { &'b [B] }
 impl_eq_for_cowvec! { &'b mut [B] }
 
-#[unstable = "waiting on PartialOrd stability"]
+#[stable]
 impl<T: PartialOrd> PartialOrd for Vec<T> {
     #[inline]
     fn partial_cmp(&self, other: &Vec<T>) -> Option<Ordering> {
@@ -659,7 +666,7 @@ impl<T: PartialOrd> PartialOrd for Vec<T> {
     }
 }
 
-#[unstable = "waiting on Eq stability"]
+#[stable]
 impl<T: Eq> Eq for Vec<T> {}
 
 #[allow(deprecated)]
@@ -669,7 +676,7 @@ impl<T: PartialEq, Sized? V: AsSlice<T>> Equiv<V> for Vec<T> {
     fn equiv(&self, other: &V) -> bool { self.as_slice() == other.as_slice() }
 }
 
-#[unstable = "waiting on Ord stability"]
+#[stable]
 impl<T: Ord> Ord for Vec<T> {
     #[inline]
     fn cmp(&self, other: &Vec<T>) -> Ordering {
diff --git a/src/libcollections/vec_map.rs b/src/libcollections/vec_map.rs
index 5ebcc736624f6..750f1458a4242 100644
--- a/src/libcollections/vec_map.rs
+++ b/src/libcollections/vec_map.rs
@@ -537,14 +537,18 @@ impl<V:Clone> VecMap<V> {
     }
 }
 
+
+#[stable]
 impl<V: PartialEq> PartialEq for VecMap<V> {
     fn eq(&self, other: &VecMap<V>) -> bool {
         iter::order::eq(self.iter(), other.iter())
     }
 }
 
+#[stable]
 impl<V: Eq> Eq for VecMap<V> {}
 
+#[stable]
 impl<V: PartialOrd> PartialOrd for VecMap<V> {
     #[inline]
     fn partial_cmp(&self, other: &VecMap<V>) -> Option<Ordering> {
@@ -552,6 +556,7 @@ impl<V: PartialOrd> PartialOrd for VecMap<V> {
     }
 }
 
+#[stable]
 impl<V: Ord> Ord for VecMap<V> {
     #[inline]
     fn cmp(&self, other: &VecMap<V>) -> Ordering {
diff --git a/src/libcore/array.rs b/src/libcore/array.rs
index e85a132ed363f..88e23377046f1 100644
--- a/src/libcore/array.rs
+++ b/src/libcore/array.rs
@@ -39,7 +39,7 @@ macro_rules! array_impls {
                 }
             }
 
-            #[unstable = "waiting for PartialEq to stabilize"]
+            #[stable]
             impl<A, B> PartialEq<[B, ..$N]> for [A, ..$N] where A: PartialEq<B> {
                 #[inline]
                 fn eq(&self, other: &[B, ..$N]) -> bool {
@@ -51,6 +51,7 @@ macro_rules! array_impls {
                 }
             }
 
+            #[stable]
             impl<'a, A, B, Rhs> PartialEq<Rhs> for [A, ..$N] where
                 A: PartialEq<B>,
                 Rhs: Deref<[B]>,
@@ -61,6 +62,7 @@ macro_rules! array_impls {
                 fn ne(&self, other: &Rhs) -> bool { PartialEq::ne(self[], &**other) }
             }
 
+            #[stable]
             impl<'a, A, B, Lhs> PartialEq<[B, ..$N]> for Lhs where
                 A: PartialEq<B>,
                 Lhs: Deref<[A]>
@@ -71,10 +73,10 @@ macro_rules! array_impls {
                 fn ne(&self, other: &[B, ..$N]) -> bool { PartialEq::ne(&**self, other[]) }
             }
 
-            #[unstable = "waiting for Eq to stabilize"]
+            #[stable]
             impl<T:Eq> Eq for [T, ..$N] { }
 
-            #[unstable = "waiting for PartialOrd to stabilize"]
+            #[stable]
             impl<T:PartialOrd> PartialOrd for [T, ..$N] {
                 #[inline]
                 fn partial_cmp(&self, other: &[T, ..$N]) -> Option<Ordering> {
@@ -98,7 +100,7 @@ macro_rules! array_impls {
                 }
             }
 
-            #[unstable = "waiting for Ord to stabilize"]
+            #[stable]
             impl<T:Ord> Ord for [T, ..$N] {
                 #[inline]
                 fn cmp(&self, other: &[T, ..$N]) -> Ordering {
diff --git a/src/libcore/borrow.rs b/src/libcore/borrow.rs
index 9bbcf67773ebb..3a2cb8ea7d984 100644
--- a/src/libcore/borrow.rs
+++ b/src/libcore/borrow.rs
@@ -200,8 +200,10 @@ impl<'a, T, Sized? B> Deref<B> for Cow<'a, T, B> where B: ToOwned<T>  {
     }
 }
 
+#[stable]
 impl<'a, T, Sized? B> Eq for Cow<'a, T, B> where B: Eq + ToOwned<T> {}
 
+#[stable]
 impl<'a, T, Sized? B> Ord for Cow<'a, T, B> where B: Ord + ToOwned<T> {
     #[inline]
     fn cmp(&self, other: &Cow<'a, T, B>) -> Ordering {
@@ -209,6 +211,7 @@ impl<'a, T, Sized? B> Ord for Cow<'a, T, B> where B: Ord + ToOwned<T> {
     }
 }
 
+#[stable]
 impl<'a, 'b, T, U, Sized? B, Sized? C> PartialEq<Cow<'b, U, C>> for Cow<'a, T, B> where
     B: PartialEq<C> + ToOwned<T>,
     C: ToOwned<U>,
@@ -219,6 +222,7 @@ impl<'a, 'b, T, U, Sized? B, Sized? C> PartialEq<Cow<'b, U, C>> for Cow<'a, T, B
     }
 }
 
+#[stable]
 impl<'a, T, Sized? B> PartialOrd for Cow<'a, T, B> where B: PartialOrd + ToOwned<T> {
     #[inline]
     fn partial_cmp(&self, other: &Cow<'a, T, B>) -> Option<Ordering> {
diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index 01a1e7f97110a..6249f7600cd22 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -224,7 +224,7 @@ impl<T:Default + Copy> Default for Cell<T> {
     }
 }
 
-#[unstable = "waiting for `PartialEq` trait to become stable"]
+#[stable]
 impl<T:PartialEq + Copy> PartialEq for Cell<T> {
     fn eq(&self, other: &Cell<T>) -> bool {
         self.get() == other.get()
@@ -358,7 +358,7 @@ impl<T:Default> Default for RefCell<T> {
     }
 }
 
-#[unstable = "waiting for `PartialEq` to become stable"]
+#[stable]
 impl<T: PartialEq> PartialEq for RefCell<T> {
     fn eq(&self, other: &RefCell<T>) -> bool {
         *self.borrow() == *other.borrow()
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index ca523db214b0c..367c794e84bb6 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -46,27 +46,37 @@ use self::Ordering::*;
 use kinds::Sized;
 use option::Option::{mod, Some, None};
 
-/// Trait for values that can be compared for equality and inequality.
+/// Trait for equality comparisons which are [partial equivalence relations](
+/// http://en.wikipedia.org/wiki/Partial_equivalence_relation).
 ///
-/// This trait allows for partial equality, for types that do not have an
+/// This trait allows for partial equality, for types that do not have a full
 /// equivalence relation. For example, in floating point numbers `NaN != NaN`,
 /// so floating point types implement `PartialEq` but not `Eq`.
 ///
+/// Formally, the equality must be (for all `a`, `b` and `c`):
+///
+/// - symmetric: `a == b` implies `b == a`; and
+/// - transitive: `a == b` and `b == c` implies `a == c`.
+///
+/// Note that these requirements mean that the trait itself must be
+/// implemented symmetrically and transitively: if `T: PartialEq<U>`
+/// and `U: PartialEq<V>` then `U: PartialEq<T>` and `T:
+/// PartialEq<V>`.
+///
 /// PartialEq only requires the `eq` method to be implemented; `ne` is defined
 /// in terms of it by default. Any manual implementation of `ne` *must* respect
 /// the rule that `eq` is a strict inverse of `ne`; that is, `!(a == b)` if and
 /// only if `a != b`.
-///
-/// Eventually, this will be implemented by default for types that implement
-/// `Eq`.
 #[lang="eq"]
-#[unstable = "Definition may change slightly after trait reform"]
+#[stable]
 pub trait PartialEq<Sized? Rhs = Self> for Sized? {
     /// This method tests for `self` and `other` values to be equal, and is used by `==`.
+    #[stable]
     fn eq(&self, other: &Rhs) -> bool;
 
     /// This method tests for `!=`.
     #[inline]
+    #[stable]
     fn ne(&self, other: &Rhs) -> bool { !self.eq(other) }
 }
 
@@ -79,8 +89,8 @@ pub trait PartialEq<Sized? Rhs = Self> for Sized? {
 /// - reflexive: `a == a`;
 /// - symmetric: `a == b` implies `b == a`; and
 /// - transitive: `a == b` and `b == c` implies `a == c`.
-#[unstable = "Definition may change slightly after trait reform"]
-pub trait Eq<Sized? Rhs = Self> for Sized?: PartialEq<Rhs> {
+#[stable]
+pub trait Eq for Sized?: PartialEq<Self> {
     // FIXME #13101: this method is used solely by #[deriving] to
     // assert that every component of a type implements #[deriving]
     // itself, the current deriving infrastructure means doing this
@@ -97,12 +107,15 @@ pub trait Eq<Sized? Rhs = Self> for Sized?: PartialEq<Rhs> {
 #[deriving(Clone, Copy, PartialEq, Show)]
 #[stable]
 pub enum Ordering {
-   /// An ordering where a compared value is less [than another].
-   Less = -1i,
-   /// An ordering where a compared value is equal [to another].
-   Equal = 0i,
-   /// An ordering where a compared value is greater [than another].
-   Greater = 1i,
+    /// An ordering where a compared value is less [than another].
+    #[stable]
+    Less = -1i,
+    /// An ordering where a compared value is equal [to another].
+    #[stable]
+    Equal = 0i,
+    /// An ordering where a compared value is greater [than another].
+    #[stable]
+    Greater = 1i,
 }
 
 impl Ordering {
@@ -126,7 +139,7 @@ impl Ordering {
     /// assert!(data == b);
     /// ```
     #[inline]
-    #[experimental]
+    #[stable]
     pub fn reverse(self) -> Ordering {
         unsafe {
             // this compiles really nicely (to a single instruction);
@@ -149,8 +162,8 @@ impl Ordering {
 ///   true; and
 /// - transitive, `a < b` and `b < c` implies `a < c`. The same must hold for
 ///   both `==` and `>`.
-#[unstable = "Definition may change slightly after trait reform"]
-pub trait Ord<Sized? Rhs = Self> for Sized?: Eq<Rhs> + PartialOrd<Rhs> {
+#[stable]
+pub trait Ord for Sized?: Eq + PartialOrd<Self> {
     /// This method returns an ordering between `self` and `other` values.
     ///
     /// By convention, `self.cmp(&other)` returns the ordering matching
@@ -161,23 +174,26 @@ pub trait Ord<Sized? Rhs = Self> for Sized?: Eq<Rhs> + PartialOrd<Rhs> {
     /// assert_eq!(10u.cmp(&5),  Greater);  // because 10 > 5
     /// assert_eq!( 5u.cmp(&5),  Equal);    // because 5 == 5
     /// ```
-    fn cmp(&self, other: &Rhs) -> Ordering;
+    #[stable]
+    fn cmp(&self, other: &Self) -> Ordering;
 }
 
-#[unstable = "Trait is unstable."]
+#[stable]
 impl Eq for Ordering {}
 
-#[unstable = "Trait is unstable."]
+#[stable]
 impl Ord for Ordering {
     #[inline]
+    #[stable]
     fn cmp(&self, other: &Ordering) -> Ordering {
         (*self as int).cmp(&(*other as int))
     }
 }
 
-#[unstable = "Trait is unstable."]
+#[stable]
 impl PartialOrd for Ordering {
     #[inline]
+    #[stable]
     fn partial_cmp(&self, other: &Ordering) -> Option<Ordering> {
         (*self as int).partial_cmp(&(*other as int))
     }
@@ -185,6 +201,17 @@ impl PartialOrd for Ordering {
 
 /// Trait for values that can be compared for a sort-order.
 ///
+/// The comparison must satisfy, for all `a`, `b` and `c`:
+///
+/// - antisymmetry: if `a < b` then `!(a > b)` and vice versa; and
+/// - transitivity: `a < b` and `b < c` implies `a < c`. The same must hold for
+///   both `==` and `>`.
+///
+/// Note that these requirements mean that the trait itself must be
+/// implemented symmetrically and transitively: if `T: PartialOrd<U>`
+/// and `U: PartialOrd<V>` then `U: PartialOrd<T>` and `T:
+/// PartialOrd<V>`.
+///
 /// PartialOrd only requires implementation of the `partial_cmp` method,
 /// with the others generated from default implementations.
 ///
@@ -193,14 +220,16 @@ impl PartialOrd for Ordering {
 /// `NaN < 0 == false` and `NaN >= 0 == false` (cf. IEEE 754-2008 section
 /// 5.11).
 #[lang="ord"]
-#[unstable = "Definition may change slightly after trait reform"]
+#[stable]
 pub trait PartialOrd<Sized? Rhs = Self> for Sized?: PartialEq<Rhs> {
     /// This method returns an ordering between `self` and `other` values
     /// if one exists.
+    #[stable]
     fn partial_cmp(&self, other: &Rhs) -> Option<Ordering>;
 
     /// This method tests less than (for `self` and `other`) and is used by the `<` operator.
     #[inline]
+    #[stable]
     fn lt(&self, other: &Rhs) -> bool {
         match self.partial_cmp(other) {
             Some(Less) => true,
@@ -210,6 +239,7 @@ pub trait PartialOrd<Sized? Rhs = Self> for Sized?: PartialEq<Rhs> {
 
     /// This method tests less than or equal to (`<=`).
     #[inline]
+    #[stable]
     fn le(&self, other: &Rhs) -> bool {
         match self.partial_cmp(other) {
             Some(Less) | Some(Equal) => true,
@@ -219,6 +249,7 @@ pub trait PartialOrd<Sized? Rhs = Self> for Sized?: PartialEq<Rhs> {
 
     /// This method tests greater than (`>`).
     #[inline]
+    #[stable]
     fn gt(&self, other: &Rhs) -> bool {
         match self.partial_cmp(other) {
             Some(Greater) => true,
@@ -228,6 +259,7 @@ pub trait PartialOrd<Sized? Rhs = Self> for Sized?: PartialEq<Rhs> {
 
     /// This method tests greater than or equal to (`>=`).
     #[inline]
+    #[stable]
     fn ge(&self, other: &Rhs) -> bool {
         match self.partial_cmp(other) {
             Some(Greater) | Some(Equal) => true,
@@ -296,7 +328,7 @@ mod impls {
 
     macro_rules! partial_eq_impl {
         ($($t:ty)*) => ($(
-            #[unstable = "Trait is unstable."]
+            #[stable]
             impl PartialEq for $t {
                 #[inline]
                 fn eq(&self, other: &$t) -> bool { (*self) == (*other) }
@@ -306,7 +338,7 @@ mod impls {
         )*)
     }
 
-    #[unstable = "Trait is unstable."]
+    #[stable]
     impl PartialEq for () {
         #[inline]
         fn eq(&self, _other: &()) -> bool { true }
@@ -320,7 +352,7 @@ mod impls {
 
     macro_rules! eq_impl {
         ($($t:ty)*) => ($(
-            #[unstable = "Trait is unstable."]
+            #[stable]
             impl Eq for $t {}
         )*)
     }
@@ -329,7 +361,7 @@ mod impls {
 
     macro_rules! partial_ord_impl {
         ($($t:ty)*) => ($(
-            #[unstable = "Trait is unstable."]
+            #[stable]
             impl PartialOrd for $t {
                 #[inline]
                 fn partial_cmp(&self, other: &$t) -> Option<Ordering> {
@@ -352,7 +384,7 @@ mod impls {
         )*)
     }
 
-    #[unstable = "Trait is unstable."]
+    #[stable]
     impl PartialOrd for () {
         #[inline]
         fn partial_cmp(&self, _: &()) -> Option<Ordering> {
@@ -360,7 +392,7 @@ mod impls {
         }
     }
 
-    #[unstable = "Trait is unstable."]
+    #[stable]
     impl PartialOrd for bool {
         #[inline]
         fn partial_cmp(&self, other: &bool) -> Option<Ordering> {
@@ -372,7 +404,7 @@ mod impls {
 
     macro_rules! ord_impl {
         ($($t:ty)*) => ($(
-            #[unstable = "Trait is unstable."]
+            #[stable]
             impl Ord for $t {
                 #[inline]
                 fn cmp(&self, other: &$t) -> Ordering {
@@ -384,13 +416,13 @@ mod impls {
         )*)
     }
 
-    #[unstable = "Trait is unstable."]
+    #[stable]
     impl Ord for () {
         #[inline]
         fn cmp(&self, _other: &()) -> Ordering { Equal }
     }
 
-    #[unstable = "Trait is unstable."]
+    #[stable]
     impl Ord for bool {
         #[inline]
         fn cmp(&self, other: &bool) -> Ordering {
@@ -402,68 +434,69 @@ mod impls {
 
     // & pointers
 
-    #[unstable = "Trait is unstable."]
+    #[stable]
     impl<'a, 'b, Sized? A, Sized? B> PartialEq<&'b B> for &'a A where A: PartialEq<B> {
         #[inline]
         fn eq(&self, other: & &'b B) -> bool { PartialEq::eq(*self, *other) }
         #[inline]
         fn ne(&self, other: & &'b B) -> bool { PartialEq::ne(*self, *other) }
     }
-    #[unstable = "Trait is unstable."]
-    impl<'a, Sized? T: PartialOrd> PartialOrd for &'a T {
+    #[stable]
+    impl<'a, 'b, Sized? A, Sized? B> PartialOrd<&'b B> for &'a A where A: PartialOrd<B> {
         #[inline]
-        fn partial_cmp(&self, other: &&'a T) -> Option<Ordering> {
+        fn partial_cmp(&self, other: &&'b B) -> Option<Ordering> {
             PartialOrd::partial_cmp(*self, *other)
         }
         #[inline]
-        fn lt(&self, other: & &'a T) -> bool { PartialOrd::lt(*self, *other) }
+        fn lt(&self, other: & &'b B) -> bool { PartialOrd::lt(*self, *other) }
         #[inline]
-        fn le(&self, other: & &'a T) -> bool { PartialOrd::le(*self, *other) }
+        fn le(&self, other: & &'b B) -> bool { PartialOrd::le(*self, *other) }
         #[inline]
-        fn ge(&self, other: & &'a T) -> bool { PartialOrd::ge(*self, *other) }
+        fn ge(&self, other: & &'b B) -> bool { PartialOrd::ge(*self, *other) }
         #[inline]
-        fn gt(&self, other: & &'a T) -> bool { PartialOrd::gt(*self, *other) }
+        fn gt(&self, other: & &'b B) -> bool { PartialOrd::gt(*self, *other) }
     }
-    #[unstable = "Trait is unstable."]
-    impl<'a, Sized? T: Ord> Ord for &'a T {
+    #[stable]
+    impl<'a, Sized? A> Ord for &'a A where A: Ord {
         #[inline]
-        fn cmp(&self, other: & &'a T) -> Ordering { Ord::cmp(*self, *other) }
+        fn cmp(&self, other: & &'a A) -> Ordering { Ord::cmp(*self, *other) }
     }
-    #[unstable = "Trait is unstable."]
-    impl<'a, Sized? T: Eq> Eq for &'a T {}
+    #[stable]
+    impl<'a, Sized? A> Eq for &'a A where A: Eq {}
 
     // &mut pointers
 
-    #[unstable = "Trait is unstable."]
+    #[stable]
     impl<'a, 'b, Sized? A, Sized? B> PartialEq<&'b mut B> for &'a mut A where A: PartialEq<B> {
         #[inline]
         fn eq(&self, other: &&'b mut B) -> bool { PartialEq::eq(*self, *other) }
         #[inline]
         fn ne(&self, other: &&'b mut B) -> bool { PartialEq::ne(*self, *other) }
     }
-    #[unstable = "Trait is unstable."]
-    impl<'a, Sized? T: PartialOrd> PartialOrd for &'a mut T {
+    #[stable]
+    impl<'a, 'b, Sized? A, Sized? B> PartialOrd<&'b mut B> for &'a mut A where A: PartialOrd<B> {
         #[inline]
-        fn partial_cmp(&self, other: &&'a mut T) -> Option<Ordering> {
+        fn partial_cmp(&self, other: &&'b mut B) -> Option<Ordering> {
             PartialOrd::partial_cmp(*self, *other)
         }
         #[inline]
-        fn lt(&self, other: &&'a mut T) -> bool { PartialOrd::lt(*self, *other) }
+        fn lt(&self, other: &&'b mut B) -> bool { PartialOrd::lt(*self, *other) }
         #[inline]
-        fn le(&self, other: &&'a mut T) -> bool { PartialOrd::le(*self, *other) }
+        fn le(&self, other: &&'b mut B) -> bool { PartialOrd::le(*self, *other) }
         #[inline]
-        fn ge(&self, other: &&'a mut T) -> bool { PartialOrd::ge(*self, *other) }
+        fn ge(&self, other: &&'b mut B) -> bool { PartialOrd::ge(*self, *other) }
         #[inline]
-        fn gt(&self, other: &&'a mut T) -> bool { PartialOrd::gt(*self, *other) }
+        fn gt(&self, other: &&'b mut B) -> bool { PartialOrd::gt(*self, *other) }
     }
-    #[unstable = "Trait is unstable."]
-    impl<'a, Sized? T: Ord> Ord for &'a mut T {
+    #[stable]
+    impl<'a, Sized? A> Ord for &'a mut A where A: Ord {
         #[inline]
-        fn cmp(&self, other: &&'a mut T) -> Ordering { Ord::cmp(*self, *other) }
+        fn cmp(&self, other: &&'a mut A) -> Ordering { Ord::cmp(*self, *other) }
     }
-    #[unstable = "Trait is unstable."]
-    impl<'a, Sized? T: Eq> Eq for &'a mut T {}
+    #[stable]
+    impl<'a, Sized? A> Eq for &'a mut A where A: Eq {}
 
+    #[stable]
     impl<'a, 'b, Sized? A, Sized? B> PartialEq<&'b mut B> for &'a A where A: PartialEq<B> {
         #[inline]
         fn eq(&self, other: &&'b mut B) -> bool { PartialEq::eq(*self, *other) }
@@ -471,6 +504,7 @@ mod impls {
         fn ne(&self, other: &&'b mut B) -> bool { PartialEq::ne(*self, *other) }
     }
 
+    #[stable]
     impl<'a, 'b, Sized? A, Sized? B> PartialEq<&'b B> for &'a mut A where A: PartialEq<B> {
         #[inline]
         fn eq(&self, other: &&'b B) -> bool { PartialEq::eq(*self, *other) }
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 75bb8d33ea85f..faf1d781465c7 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -379,6 +379,7 @@ impl<T> MutPtrExt<T> for *mut T {
 }
 
 // Equality for pointers
+#[stable]
 impl<T> PartialEq for *const T {
     #[inline]
     fn eq(&self, other: &*const T) -> bool {
@@ -388,8 +389,10 @@ impl<T> PartialEq for *const T {
     fn ne(&self, other: &*const T) -> bool { !self.eq(other) }
 }
 
+#[stable]
 impl<T> Eq for *const T {}
 
+#[stable]
 impl<T> PartialEq for *mut T {
     #[inline]
     fn eq(&self, other: &*mut T) -> bool {
@@ -399,6 +402,7 @@ impl<T> PartialEq for *mut T {
     fn ne(&self, other: &*mut T) -> bool { !self.eq(other) }
 }
 
+#[stable]
 impl<T> Eq for *mut T {}
 
 // Equivalence for pointers
@@ -439,6 +443,7 @@ mod externfnpointers {
     use mem;
     use cmp::PartialEq;
 
+    #[stable]
     impl<_R> PartialEq for extern "C" fn() -> _R {
         #[inline]
         fn eq(&self, other: &extern "C" fn() -> _R) -> bool {
@@ -449,6 +454,7 @@ mod externfnpointers {
     }
     macro_rules! fnptreq {
         ($($p:ident),*) => {
+            #[stable]
             impl<_R,$($p),*> PartialEq for extern "C" fn($($p),*) -> _R {
                 #[inline]
                 fn eq(&self, other: &extern "C" fn($($p),*) -> _R) -> bool {
@@ -468,6 +474,7 @@ mod externfnpointers {
 }
 
 // Comparison for pointers
+#[stable]
 impl<T> Ord for *const T {
     #[inline]
     fn cmp(&self, other: &*const T) -> Ordering {
@@ -481,6 +488,7 @@ impl<T> Ord for *const T {
     }
 }
 
+#[stable]
 impl<T> PartialOrd for *const T {
     #[inline]
     fn partial_cmp(&self, other: &*const T) -> Option<Ordering> {
@@ -500,6 +508,7 @@ impl<T> PartialOrd for *const T {
     fn ge(&self, other: &*const T) -> bool { *self >= *other }
 }
 
+#[stable]
 impl<T> Ord for *mut T {
     #[inline]
     fn cmp(&self, other: &*mut T) -> Ordering {
@@ -513,6 +522,7 @@ impl<T> Ord for *mut T {
     }
 }
 
+#[stable]
 impl<T> PartialOrd for *mut T {
     #[inline]
     fn partial_cmp(&self, other: &*mut T) -> Option<Ordering> {
diff --git a/src/libcore/slice.rs b/src/libcore/slice.rs
index f356a0867d252..77bb5cc2499c8 100644
--- a/src/libcore/slice.rs
+++ b/src/libcore/slice.rs
@@ -1437,7 +1437,7 @@ pub mod bytes {
 // Boilerplate traits
 //
 
-#[unstable = "waiting for DST"]
+#[stable]
 impl<A, B> PartialEq<[B]> for [A] where A: PartialEq<B> {
     fn eq(&self, other: &[B]) -> bool {
         self.len() == other.len() &&
@@ -1449,7 +1449,7 @@ impl<A, B> PartialEq<[B]> for [A] where A: PartialEq<B> {
     }
 }
 
-#[unstable = "waiting for DST"]
+#[stable]
 impl<T: Eq> Eq for [T] {}
 
 #[allow(deprecated)]
@@ -1466,14 +1466,14 @@ impl<'a,T:PartialEq, Sized? V: AsSlice<T>> Equiv<V> for &'a mut [T] {
     fn equiv(&self, other: &V) -> bool { self.as_slice() == other.as_slice() }
 }
 
-#[unstable = "waiting for DST"]
+#[stable]
 impl<T: Ord> Ord for [T] {
     fn cmp(&self, other: &[T]) -> Ordering {
         order::cmp(self.iter(), other.iter())
     }
 }
 
-#[unstable = "waiting for DST"]
+#[stable]
 impl<T: PartialOrd> PartialOrd for [T] {
     #[inline]
     fn partial_cmp(&self, other: &[T]) -> Option<Ordering> {
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 8db672b265375..59cf79408b100 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -1143,6 +1143,7 @@ pub mod traits {
     use ops;
     use str::{Str, StrExt, eq_slice};
 
+    #[stable]
     impl Ord for str {
         #[inline]
         fn cmp(&self, other: &str) -> Ordering {
@@ -1158,6 +1159,7 @@ pub mod traits {
         }
     }
 
+    #[stable]
     impl PartialEq for str {
         #[inline]
         fn eq(&self, other: &str) -> bool {
@@ -1167,8 +1169,10 @@ pub mod traits {
         fn ne(&self, other: &str) -> bool { !(*self).eq(other) }
     }
 
+    #[stable]
     impl Eq for str {}
 
+    #[stable]
     impl PartialOrd for str {
         #[inline]
         fn partial_cmp(&self, other: &str) -> Option<Ordering> {
diff --git a/src/libcore/tuple.rs b/src/libcore/tuple.rs
index a92914c99e35b..576989fabe77c 100644
--- a/src/libcore/tuple.rs
+++ b/src/libcore/tuple.rs
@@ -132,7 +132,7 @@ macro_rules! tuple_impls {
                 }
             }
 
-            #[unstable = "waiting for PartialEq to stabilize"]
+            #[stable]
             impl<$($T:PartialEq),+> PartialEq for ($($T,)+) {
                 #[inline]
                 fn eq(&self, other: &($($T,)+)) -> bool {
@@ -144,10 +144,10 @@ macro_rules! tuple_impls {
                 }
             }
 
-            #[unstable = "waiting for Eq to stabilize"]
+            #[stable]
             impl<$($T:Eq),+> Eq for ($($T,)+) {}
 
-            #[unstable = "waiting for PartialOrd to stabilize"]
+            #[stable]
             impl<$($T:PartialOrd + PartialEq),+> PartialOrd for ($($T,)+) {
                 #[inline]
                 fn partial_cmp(&self, other: &($($T,)+)) -> Option<Ordering> {
@@ -171,7 +171,7 @@ macro_rules! tuple_impls {
                 }
             }
 
-            #[unstable = "waiting for Ord to stabilize"]
+            #[stable]
             impl<$($T:Ord),+> Ord for ($($T,)+) {
                 #[inline]
                 fn cmp(&self, other: &($($T,)+)) -> Ordering {
diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 7b7473b2c993c..b473a665c76b1 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -1261,6 +1261,7 @@ impl<K: Eq + Hash<S>, V: Clone, S, H: Hasher<S>> HashMap<K, V, H> {
     }
 }
 
+#[stable]
 impl<K: Eq + Hash<S>, V: PartialEq, S, H: Hasher<S>> PartialEq for HashMap<K, V, H> {
     fn eq(&self, other: &HashMap<K, V, H>) -> bool {
         if self.len() != other.len() { return false; }
@@ -1271,6 +1272,7 @@ impl<K: Eq + Hash<S>, V: PartialEq, S, H: Hasher<S>> PartialEq for HashMap<K, V,
     }
 }
 
+#[stable]
 impl<K: Eq + Hash<S>, V: Eq, S, H: Hasher<S>> Eq for HashMap<K, V, H> {}
 
 impl<K: Eq + Hash<S> + Show, V: Show, S, H: Hasher<S>> Show for HashMap<K, V, H> {
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index 6d83d5510b357..93f6895f6885b 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -572,6 +572,7 @@ impl<T: Eq + Hash<S>, S, H: Hasher<S>> HashSet<T, H> {
     }
 }
 
+#[stable]
 impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialEq for HashSet<T, H> {
     fn eq(&self, other: &HashSet<T, H>) -> bool {
         if self.len() != other.len() { return false; }
@@ -580,6 +581,7 @@ impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialEq for HashSet<T, H> {
     }
 }
 
+#[stable]
 impl<T: Eq + Hash<S>, S, H: Hasher<S>> Eq for HashSet<T, H> {}
 
 impl<T: Eq + Hash<S> + fmt::Show, S, H: Hasher<S>> fmt::Show for HashSet<T, H> {