M.U.G.E.N.?

[SLjimbolian]

I've just heard about it recently, seems to be the ultimate in a fanboy's wet dream. I'd sure as hell love to give this game (or program) a try, but I got nothing it terms of downloading preloaded stuff. Plus, I think you can only get it for Linux nowadays.

More info: http://en.wikipedia.org/wiki/M.U.G.E.N