AMD has yet to release a stable driver with OpenGL 4.3 support
Nvidia has announced that yet another driver is now available for download, 326.98, providing improved support for OpenGL 4.4 and GLSL 4.40, albeit it's still in the Beta stages.This is not the first driver with OpenGL 4.4 and GLSL 4.4 from Nvidia, but AMD still hasn't released a stable driver that provides support for OpenGL 4.3.
In order to get this enhanced support for the video card, users will need a Fermi- or Kepler-based GPU. The platforms supporting this functionality are GeForce 400, 500, 600, 700, and the Quadro series (K600, K5000, K4000, K2000D, K2000, 6000, 600, 5000, 410, 4000, 400, 2000D, 2000).
Download the Nvidia Display Driver 325.05.03 for Linux.
Download the Nvidia Display Driver 325.05.03 for FreeBSD.
Download the Nvidia Display Driver 325.05.03 for Solaris.
Check out the official announcement for a complete list of fixes and improvements.