Compiz is one of the first compositing window managers for the X Window System that is able to take advantage of OpenGL-acceleration. The integration allows it to perform compositing effects in window management, such as a minimization effect and a cube workspace. Compiz conforms to the ICCCM standard and as such can substitute for the default Metacity in GNOME or KWin in KDE. Compiz brings some of the features found in competitors, such as Exposé in Apple's Mac OS X and a new Alt-Tab application-switcher, similar to the one found in Microsoft's Windows Vista. Compiz is built on the Composite extension to X and the GLX_EXT_texture_from_pixmap extension to OpenGL.