In this appendix I will provide you with a brief introduction to the OpenGL programming interface. This API, introduced in the early 1990s by Silicon Graphics, has been (and still is) an industry cornerstone because of its simplicity, elegance, and cross-compatibility. OpenGL is supported by many platforms, and its design methodology has become a guiding light for many APIs on different platforms.
Learning OpenGL provides a two-way benefit. First, OpenGL is available in numerous platforms. Second, most platforms that do not use OpenGL depend on APIs that have been heavily influenced by it, so having knowledge of OpenGL makes it really easy to learn most other APIs.
OpenGL is an excellent tool for anything from early-concept prototyping to independent game development and full title production. Being an open, platform-neutral standard, OpenGL enables you to connect with a huge user base, which provides information and code examples you can use to quickly get working.