Mesa 9.0.1 is a bug fix release which fixes bugs found since the 9.0 release.
Mesa 9.0 implements the OpenGL 3.1 API, but the version reported by glGetString(GL_VERSION) or glGetIntegerv(GL_MAJOR_VERSION) / glGetIntegerv(GL_MINOR_VERSION) depends on the particular driver being used. Some drivers don't support all the features required in OpenGL 3.1. OpenGL 3.1 is only available if requested at context creation because GL_ARB_compatibility is not supported.
TBD.
None.
This list is likely incomplete.
The full set of changes can be viewed by using the following GIT command:
git log mesa-9.0..