Hi, For those who live on the bleeding edge, I have made a port of the latest development version of ghc for OS X through MacPorts. (If you are not familiar with MacPorts, see http://macports.org.) The build is from the darcs repository, and installs its binaries as <bin_name>-6.7.<date_code> . This naming allows the development version to be installed alongside the released ghc-6.6 with no conflicts. The port should work with OS X 10.3 and later on Intel or PPC. The name of the port is "ghc-devel". Note that because this is really a _development_ version, it may be buggy or not build at all. For day to day use you want the released ghc-6.6. Have fun, Greg