Music:Billy Bragg and Wilco - Mermaid Avenue Volume II - My Flying Saucer
.NET - meet Mac OS X
Rotor, the shared source implementation of .the NET CLR (along with chunks of the SDK and the C# language) now has an official build for Mac OS X. Command line only for the moment, but I'm sure greater minds than mine are working on the Cocoa bindings.
From the MSDN site it appears that requirements won't be too rigorous - on Mac OS X you will need: