+This should be a stable release. We have not made major changes
+since 4.04 to the core compiler, but we have fixed lots of bugs.
+We believe that 4.06 is in a nice stable well-tested state. (Ha!)
+
+Apart from that, there are the following changes
+
+ - Major library reorganisation. All libraries, except the ones that
+ are part of the Haskell 98 *language* specification, have moved to
+ fptools/hslibs/. The hslibs tree is independent of GHC, shared between
+ GHC, Hugs, and (we hope) other Haskell implementations.
+ The idea is to make it easier for people to contribute and maintain
+ libraries.
+
+ The hslibs/ tree is organised in a Java-like fashion. Details in
+ the new Library guide:
+ http://www.haskell.org/ghc/docs/4.06/hslibs/book1.html
+
+ Existing programs that use the -syslib flag may need to change which
+ syslibs they include.
+
+ - Support for "foreign export dynamic".
+
+ - Clean up of concurrent I/O system; in particular, I/O is now non-blocking,
+ except (alas) on stdout/stderr for tiresome reasons.
+
+ - Some refinements to the exceptions mechanism:
+ http://www.haskell.org/ghc/docs/4.06/users_guide/release-4-06.html#exc-changes-406