Prior to DirectX, Microsoft had included OpenGL on their Windows NT platform. At the time, OpenGL required "high-end" hardware and was focused on engineering and CAD uses. Direct3D was intended to be a Microsoft controlled alternative to OpenGL, focused initially on game use. As 3D gaming grew, OpenGL developed to include better support for programming techniques for interactive multimedia applications like games, giving developers choice between using OpenGL or Direct3D as the 3D graphics API for their applications. At that point a "battle" began between supporters of the cross-platform OpenGL and the Windows-only Direct3D. Incidentally, OpenGL was supported at Microsoft by the DirectX team. If a developer chose to use OpenGL 3D graphics API, the other APIs of DirectX are often combined with OpenGL in computer games because OpenGL does not include all of DirectX's functionality (such as sound or joystick support).