The X Window System provides the base technology for developing graphical user interfaces. At a very basic level, X draws the elements of the GUI on the user's screen and builds in methods for sending user interactions back to the application. Using application GUI development toolkits, such as Motif, an application developer can quickly create an application interface to the end user. Included in this package are all of the libraries, header files needed to develop X11 applications, as well as the X11 display server for displaying your applications. Also included are many common X11 client applications, such as xcalc, xterm, and xclock.