as a separate standalone extension instead of being part of DRI3. Apart from allowing non-GL X clients to synchronize with VBLANK, Present brings other advantages. DRI3 graphics performance is better because Present is more efficient than DRI2 in swapping buffers. A number of OpenGL extensions that weren't available with DRI2 are now supported based on new features provided by Present. Present provides two main operations to X clients: update a region of a window using part of or all the contents of a pixmap () and set the type of presentation events related to a certain window that the client wants to be notified about (). There are three presentation events about which a window can notify an X client: when an ongoing presentation operation —normally from a call to — has been completed (), when a pixmap used by a operation is ready to be reused () and when the window configuration —mostly window size— changes (). Whether a operation performs a direct copy (blit) onto the front buffer or a swap of the entire back buffer with the front buffer is an internal detail of the Present extension implementation, instead of an explicit choice of the X client as it was in DRI2. Adoption Several open source DRI drivers have been written, including ones for ATI Mach64, ATI Rage128, ATI Radeon, 3dfx Voodoo3 through Voodoo5, Matrox G200 through G400, SiS 300-series, Intel i810 through i965, S3 Savage, VIA UniChrome graphics chipsets, and nouveau for Nvidia. Some graphics vendors have written closed-source DRI drivers, including ATI and PowerVR Kyro. The various versions of DRI have been implemented by various operating systems, amongst others by the Linux kernel, FreeBSD, NetBSD, OpenBSD, and OpenSolaris. History The project was started by Jens Owen and Kevin E. Martin from Precision Insight (funded by Silicon Graphics and Red Hat). It was first made widely available as part of XFree86 4.0 and is now part of the X.Org Server. It is currently maintained by the free software community. Work on DRI2 started at the 2007 X Developers' Summit from a Kristian Høgsberg's proposal. Høgsberg himself wrote the new DRI2 extension and the modifications to Mesa and GLX. In March 2008 DRI2 was mostly done, but it couldn't make into X.Org Server version 1.5 and had to wait until version 1.6 from February 2009. The DRI2 extension was officially included in the X11R7.5 release of October