C++ and OpenGL, it'll give the Linux/Mac users something to be happy about as long as you make it so that it'll run on them OS's (OpenGL works on Windows, Linux, Mac and possibly some others).
If you need help, theirs always people who know C++ you can go to.
Helios and aab (if he's still alive
) are the first ones that come to mind. I could also try to help, though I'm more DirectX than OpenGL, but it's still C++