The GeForce 2 series (NV15) is the second generation of Nvidia's GeForce graphics processing units (GPUs). Introduced in 2000, it is the successor to the GeForce 256. The GeForce 2 family comprised a number of models: GeForce 2 GTS, GeForce 2 Pro, GeForce 2 Ultra, GeForce 2 Ti, GeForce 2 Go and the GeForce 2 MX series. In addition, the GeForce 2 architecture is used for the Quadro series on the Quadro 2 Pro, 2 MXR, and 2 EX cards with special drivers meant to accelerate computer-aided design applications.