XFree86 is a software distribution from The XFree86 Project, Inc. XFree86 is a free distribution of the X Windows System originally devoloped at MIT. The software runs on a number of Unix-like operating systems such as Linux. It was originally developed for the Intel x86 series of processors but is being ported to other platforms. The XFree86 code and related X servers is primarily responsible for providing an interface to the graphics hardware of the system. Other software such as window managers (like Sawfish and tvm) and desktop environments (such as Gnome and KDE) is uses to provide a complete graphical user interface.

Though most installations will have an automated process for setting up XFree86, sometimes getting X to work is a real pain.