A graphical user interface utilized on systems supporting the X Window System and, in fact, the most widely utilized graphical user interface system on UNIX and Linux computers. The CDE delineates a standardized set of functional capabilities and supporting infrastructure. The CDE also delineates relevant command-line actions, data interchange formats, standard application programming interfaces, and protocols that need to be supported by a system conforming to the standard. The CDE also provides standardized forms of the facilities usually found in a graphical user interface environment, such as application building and integration services, calculator, calendar and appointments management, electronic mail, file management, print job services, session management, text editing, windowing and window management, and a help service. The Open Group. Common Desktop Environment. [Online, 1998.] The Open Group Website. http://www.opengroup.org/branding/prodstds/x98xd.htm.