At least you can fork it internally though and support it if need be. The same is not the case with something like XNA which is so tied into the OS that when they drop it, you're up shit creek.
True, thought it is important to be realistic about your ability in terms of time/skills to do so.
For OSS I like for one of three things. Either "too big to fail" (i.e Linux , Rails). Interchangeability , i.e something built on top of an open protocol like an SMTP server. Or something with < ~10KLOC in language I am familiar enough with that I would feel comfortable folding the entire thing into the codebase as a whitebox.
> The same is not the case with something like XNA which is so tied into the OS that when they drop it, you're up shit creek.
While you can't fork XNA and support it, it's not even remotely tied to the OS. It's a content pipeline and a thin wrapper around DirectX's various components. There's really nothing magical there, and certainly no low-level pieces.
