Unreal Engine and Unity are widely adopted engines used to develop some of the best games on the market today.
Voted Best Game Engine time and again. The engine of choice for Gears of War, Infinity Blade, and more big titles.
Develop once, publish everywhere! Unity is the ultimate tool for video game development.
DirectX and OpenGL are industry standard API's for graphics programming. They both support programmable shaders. OpenGL is an open standard and is available on Windows, Mac and Linux. OpenGL ES is the graphics API used in Android Devices.
OpenGL/OpenGL ES - The Industry Standard for High Performance Graphics
DirectX - The software behind the eye-popping 3-D visuals and immersive sound effects found in many of today's PC games.