The Direct Rendering Infrastructure, also known as the DRI, is a framework for allowing direct access to graphics hardware under the X Window System in a safe and efficient manner. It includes changes to the X server, to several client libraries, and to the kernel (DRM, Direct Rendering Manager). The most important use for the DRI is to create fast OpenGL implementations providing hardware acceleration for Mesa. Several 3D accelerated drivers have been written to the DRI specification, including drivers for chipsets produced by 3DFX, AMD (formerly ATI), Intel and Matrox.