Direct Rendering Infrastructure

The Direct Rendering Infrastructure (DRI) is the framework comprising the modern Linux graphics stack which allows unprivileged user-space programs to issue commands to graphics hardware without conflicting with other programs. The main use of DRI is to provide hardware acceleration for the Mesa implementation of OpenGL. DRI has also been adapted to provide OpenGL acceleration on a framebuffer console without a display server running.

Source: Wikipedia — Direct Rendering Infrastructure (CC BY-SA 4.0)