The CxXBar WDM Crossbar driver is a Windows Device Manager (WDM) driver used primarily for managing crossbar switch devices in systems that handle multiple video or audio streams, such as video capture cards or multi-input/output (I/O) devices.

A crossbar switch (also called a video crosspoint switch) is a type of hardware that allows different video or audio signals to be routed to different outputs. In the context of computer systems, this is typically used in devices like capture cards, TV tuners, and multi-channel audio interfaces.

The CxXBar WDM driver typically enables functionality for video and audio stream routing and management by allowing the system to recognize and control the crossbar hardware for input and output channels.