The `nvidia-settings` utility is a tool for configuring the NVIDIA
XFree86/X.org graphics driver. It operates by communicating with the NVIDIA
X driver, querying and updating state as appropriate. This
communication is done with the NV-CONTROL X extension.

Values such as brightness and gamma, XVideo attributes, temperature,
and OpenGL settings can be queried and configured via nvidia-settings.

WWW: http://www.nvidia.com/object/unix.html