You right. The idea is that there are some people (me included) that are forced to use a Windows machine a few hours a day. I have an iMac at home on which I t

You right. The idea is that there are some people (me included) that are forced to use a Windows machine a few hours a day. I have an iMac at home on which I test/compile my code from time to time. From my experience you can safely implement on Windows about 90% of an application, because I restrain myself to use only the functions that are compatible with both OpenGL ES and OpenGL I'm able to implement parts of the graphical components of my app too. This is an incremental process and I always check,in the evening, on my iMac. Take a game of Tic Tac Toe for example, you can implement the computer movements (game AI) on GNUstep. You can also use Blender to create your graphical objects ... In the end only about 10% of the code actually needs a real Mac.