Win32 to X11 Migration?

Hos writes "I had a good, original idea for a game that I wanted to write for X11. Unfortunately I know nothing about X programming, so I decided to write a prototype version using the Win32 API. Now that this works, I would like to port it to X11 and complete it. Can anyone recommend any good references for beginning X programming? I've seen the Xlib and Motif O'Reilly books at the book store. Should I get these? Are there any libraries I should avoid? Any good websites? " As near as I can understand it, moving between X and Win32 isn't exactly a direct affair. Would you all suggest this? Or would porting first to GTK for Win32 and then moving that code to the Unix make more sense?