An anonymous reader writes "The Mesa developers released Mesa 9.0 with open-source OpenGL 3.1 driver support. This de facto OpenGL Linux implementation now supports the several year old OpenGL 3.1 specification for Intel hardware while the other drivers are still at OpenGL 3.0 or worse. Other features to Mesa 9.0 include completing MPEG1/MPEG2 video acceleration, early OpenCL support, bug-fixes, and new hardware support."
OpenGL 3.1 support is limited to Intel hardware, but at least ATI/AMD hardware supports some of OpenGL 3.1. A few features from OpenGL 4 were also added.