Earlier quoted context omitted.
there is a mingw port for windows. untested by me, but it looks credible. as for os x, that's all i use, and git works PAINLESSLY on it. i'm not sure where you got this information from.
Git works on OS X and Windows, but it isn't quite as fast (many of its speed optimizations are coupled with aspects of the Linux filesystem), and its maintainers are placing low priority on portability. I never said it didn't work, just that it isn't especially important to them. That raises a lot of red flags for me. I work on amd64/i386/sparc OpenBSD at home and Windows at work, and I think version control systems…
Could you give me a reference to "git is not quite as fast on OS X" because I certainly haven't noticed it. On windows I could feel how slow it was, but not on OS X.