NVIDIA Corporation - (Freeware)
NVIDIA nForce® media and communications processors (MCPs) are the key ingredient in the best motherboards for NVIDIA. Designed specifically for gamers and multimedia enthusiasts, nForce MCPs are available for both AMD and Intel platforms. nForce MCPs continue to push the limits of innovation with their support for ESA, Quad and 3-way SLI, as well as NVIDIA® Hybrid SLI® technology.
Each OS has it's own version of NVIDIA nForce.