The ATI WDM Rage Theater Video NSP (Video Capture) driver is part of the software package for ATI's (now AMD) Rage Theater chip, which was used in ATI graphics cards and video capture hardware. Specifically, the Rage Theater chip was designed to handle video input and output functions, such as analog TV signal reception or video capture from external sources. "WDM" stands for Windows Driver Model, a framework for drivers in modern versions of Windows that provides greater stability and compatibility with different hardware and software.

The Rage Theater Video NSP is related to the video capture functionality of the Rage Theater chip, and it is often necessary to install this driver if you're using older ATI graphics cards that support video capture or TV tuning features.