OpenGL 2.1 Reference Pages

Use the index at the left to choose any GL, GLU, or GLX reference page for viewing. The reference pages (also known as "man pages") include all of the important usage information for each command. This information includes a description of all parameters, return values, error conditions, and related commands.

Browser Compatibility

Many of the reference pages depend on relatively complex math equations. We've chosen the industry standard, MathML, for rendering our equations. This standard is gaining widespread support, but there are still some growing pains. Here's what you can expect from different browsers:

Downloading Man Page Sources

The Docbook XML source for the man pages is available for anonymous checkout in Khronos' Subversion server, and you can build a man page distribution of your own using open source tools. See the technical Wiki pages describing the XML Toolchain and Man Pages for more information.


If you find any inaccuracies or typos in the reference pages, don't hesitate to inform us via the Khronos Bugzilla (you must first create a Bugzilla account, however).