We are pleased to announce the first release candidate for GHC 7.4.1: http://www.haskell.org/ghc/dist/7.4.1-rc1/ This includes the source tarball, installers for OS X and Windows, and bindists for amd64/Linux, i386/Linux, amd64/FreeBSD and i386/FreeBSD. Please test as much as possible; bugs are much cheaper if we find them before the release! The release notes are not yet available, but here are some of the highlights of the 7.4 branch since 7.2 and 7.0: * There is a new feature Safe Haskell (-XSafe, -XTrustworthy, -XUnsafe): http://www.haskell.org/ghc/dist/stable/docs/html/users_guide/safe-haskell.ht... The design has changed since 7.2. * There is a new feature kind polymorphism (-XPolyKinds): http://www.haskell.org/ghc/dist/stable/docs/html/users_guide/kind-polymorphi... A side-effect of this is that, when the extension is not enabled, in certain circumstances kinds are now defaulted to * rather than being inferred. * There is a new feature constraint kinds (-XConstraintKinds): http://www.haskell.org/ghc/dist/stable/docs/html/users_guide/constraint-kind... * It is now possible to give any sort of declaration at the ghci prompt: http://www.haskell.org/ghc/dist/stable/docs/html/users_guide/interactive-eva... For example, you can now declare datatypes within ghci. * The profiling and hpc implementations have been merged and overhauled. Visible changes include renaming of profiling flags: http://www.haskell.org/ghc/dist/stable/docs/html/users_guide/flag-reference.... and the cost-centre stacks have a new semantics, which should in most cases result in more useful and intuitive profiles. The +RTS -xc flag now also gives a stack trace. * It is now possible to write compiler plugins: http://www.haskell.org/ghc/dist/stable/docs/html/users_guide/compiler-plugin... * DPH support has been significantly improved. * There is now preliminary support for registerised compilation using LLVM on the ARM platform. Note: The release candidate accidentally includes the random, primitive, vector and dph libraries. The final release will not include them. Thanks Ian, on behalf of the GHC team