http://programmers.stackexchange.com/questions/60544/why-do-game-developers-prefer-windows tl;dr OpenGL had many functions like multitexturing, shaders, hardware T&L support for quite a long time…. with vendor-specific extensions. MS had a lot of time to mess up and learn, and it didn’t help that there were so many complete rewrites of OpenGL by so many different vendors before the ARB came in and provided their half-hearted fixes. Fast forward to the launch of Vista; MS slipped up again by not providing D3D10 support on XP; and Vista was, well, not the best OS of its time. D3D10 hardware runs D3D9 like a walk in the park, and game developers still provide DX9 compatibility (a year later and Crysis still supports DX9.) OpenGL got their stuff together too late with the release of OpenGL 3.0 with GLSL, and Win7+DX11 is taking everyone by storm. New cards like the HD 5850 are nearly twice as fast as the previous ATI RV770 cards, and OpenGL goes back to picking up the mess made after their mad race.