OpenGL接口包含了数百个函数，图形程序员可以利用这些函数指定设计高品质的三维彩色图像所需的对象和操作。这些函数中有许多实际上是其他函数的简单变形，因此，实际上它仅包含大约180个左右完全不同的函数。 OpenGL 实用库（OpenGL Utility Library，GLU）和对X窗口系统的OpenGL扩展（OpenGL Extension to the X Window System，GLX）为OpenGL提供了有用的支持特性和完整的OpenGL核心函数集。本书详细介绍了这些函数的功能。
GLFW库是一个免费、开源、支持多平台的OpenGL扩展库，主要用于管理输入，包括键盘、鼠标输入等。 GLFW is a free, Open Source, multi-platform library for creating OpenGL contexts and managing input, including keyboard, mouse, joystick and time. It is intended to be simple to integrate into exist
GLFW is a portable framework for OpenGL application development. It handles operating system specific tasks such OpenGL window management, resolution switching, keyboard, mouse and joystick input, timer input, creating threads, and more.
GLee (GL Easy Extension library) is a free cross-platform extension loading library for OpenGL. It provides seamless support for OpenGL functions up to version 3.0 and nearly 400 extensions.
