The OpenGL® API (Application Programming Interface) is a software interface to graphics hardware. It is the most widely used environment for developing 2D and 3D graphics applications. It is a low-level standard specification, vendor-neutral interface that works on a variety of computer platforms, hiding the complexities of the underlying graphic system. The interface is very flexible, rich in functionality and designed for maximizing render performance. There are hundreds of functions, and many more OpenGL extensions defined by vendors and work groups. OpenGL is supported on Windows, Linux, Mac OS X, Solaris and all major operating systems. OpenGL can be used on PCs, Workstations and Supercomputers and can be called from most programming languages. On some platforms, especially mobile phones, handhelds and game consoles, a reduced API OpenGL ES is often used.
OpenGL based applications are widely used in the industry in markets such as CAD, entertainment, game development, manufacturing, medical, visualization and virtual reality. The OpenGL API was developed in 1992 by SGI® and is evolving since. It is now being managed under the Khronos Group consortium as an open standard API.
Software developers do not need to license OpenGL to use it in their applications. They can simply link to a library provided by a hardware vendor. The OpenGL API provides developers with a complete set of graphic functions to visualize and animate their 3D models. The design of the API gives the developer a lot of freedom, but requires a deep understanding of the graphics pipeline to render what he wishes in the most efficient way. OpenGL API is well documented both online and in printed materials.