The OpenGL 4.0 specification was released towards the middle of March alongside an OpenGL 3.3 update, which NVIDIA was quick to capitalize upon the 3.x update just days later with new drivers for supported operating systems. NVIDIA wasn't immediate in delivering OpenGL 4.0 support, since they didn't have any hardware at the time capable of supporting this newest specification. Now that the GeForce GTX 470/480 GPUs are out there and other new DirectX 11.0 / OpenGL 4.0 capable hardware is on the way, NVIDIA has put out its OpenGL 4.0 driver update for Linux and Windows.
The new Linux driver is 195.36.07.04 and provides full support for OpenGL 4.0 with GLSL 4.00 (GL Shading Language 4) and for the older non-GL4 capable hardware it has OpenGL 3.3 with GLSL 3.30. This new OpenGL 4 NVIDIA Linux driver can be found on their developer page.
With AMD having had DirectX 11.0 / OpenGL 4.0 capable hardware around for months, they beat NVIDIA to delivering GL4 Linux support, which took place late last month. AMD's Radeon HD 5000 "Evergreen" series (such as the Radeon HD 5750 and Radeon HD 5770 that we reviewed last October) is compatible with OpenGL 4.0 and so is their just-launched ATI FirePro V8800.
For those in the market for a NVIDIA upgrade, the Fermi hardware is starting to be found at major Internet retailers for pre-order. You can find them at NewEgg and Amazon. When shopping please use our affiliate links so that we can continue to support these operations here at Phoronix.
Amazon has a variety of Fermi graphics cards from the $350 USD Zotac GeForce GTX 470 to a "Superclocked" EVGA GeForce GTX 470 for $400, or the GeForce GTX 480 that goes for $500.