Mesa is a 3-D graphics library with an API which is very similar to that
of OpenGL*.  To the extent that Mesa utilizes the OpenGL command syntax or 
state machine, it is being used with authorization from Silicon Graphics, 
Inc.  However, the author makes no claim that Mesa is in any way a 
compatible replacement for OpenGL or associated with Silicon Graphics, Inc.

This is a Mangled version of Mesa in order to do off-screen rendering in 
other packages like VTK. Offscreen rendering is useful for a 
number of things, such as batch processing, parallel processing, and 
remote processing.

WWW: http://www.mesa3d.org/