OpenGL® ES is the de-facto standard for 3D graphics on embedded systems. It is a light-weighted version of the OpenGL specification intended for embedded devices such as mobile phones, PDAs and consoles. It makes it easy to create 3D graphics applications and games across all major mobiles and embedded platforms.
Due to the variety of the embedded industry, the specification is built to support both low-end cell phones and high-end gaming consoles. OpenGL ES has a broad support in the industry; it is supported on: Apple iPhone, Google Android, Sony Playstation 3, and more. OpenGL ES API is managed by the Khronos Group consortium for open standard APIs.
Software developers do not need to license OpenGL ES to use it to create their applications. They can simply link to a library provided by a hardware vendor. OpenGL ES is designed to maximize 2D and 3D render performance while requiring minimum data storage, battery consumption and CPU resources. OpenGL ES API can be implemented using a dedicated graphic hardware (GPU) or using software routines, running on the CPU. Developers can easily translate their desktop OpenGL applications to OpenGL ES applications.
OpenGL ES - Official website
Wikipedia article