Sam Gentile announced the release of
Rotor 1.0 today. Rotor is a Microsoft implementation of the Dot-Net Common Language Infrastructure (CLI) and C# that is released in source code form for Windows XP, Mac OSX, and FreeBSD. Note that the Rotor
license is NOT open source. If you want an open source implementation of the Dot-Net technologies, look at
Mono which is licensed under GPL and LGPL.