I'm taking various older versions of the OS/2 based EMX port of GCC and re-hosting them on Win32. This way I can use multiple core machines to build my OS/2 side projects.
several vaguely related projects worked on by me: a 3d engine with a javascript-like scripting language (pdsys); an older scheme dialect (vmsys); ... (2009-04-28: I have been gone for years, may try to put up some newer stuff...).
MacPerl supports the Perl programming language on Mac OS (not Mac OS X). Mac OS 8.1 - 9.x are supported; 7.5.5 is supported by the MPW tool and older versions of the app. 5.6.1r2 is the current version (based on perl 5.6.1); MacPerl 5.8 is in development