I'm learning the Win32 API, but I'd also like to learn the standard C APIs for Windowing in other systems once I'm done. I've tried Googling, but the few relevant results that were brought up seemed to conflict with eachother, and I had no idea what was a reliable source and what wasn't. What I'm interested in is primarily the API for the Mac and it's sister systems (I'm really not sure how Apple fits in there...), and then if there is a generally accepted windowing library for use in Linux systems I'd like to learn some more about that.
