IMPORTANT for Developer
As the moment ( or since few months:) mesa start to support GEOMETRY SHADERS on intel ivy bridge and later
platform.i tested it on my ivy bridge graphics laptop.Then i saw that it was work perfectly.
Also it is not require stupit extensions like "GL_ARB_geometry_shader4" because of OpenGL 3.3 core profile supported by mesa and geometry shaders into core since version 3.2.
Supporting of others vendors (nvidia,amd) coming soon.i hope a few mounts.