X Window System

X Window System a client/server system for running a graphical user interface (GUI) that uses windows in a UNIX environment.

What is X Window System?

A client/server system for running a graphical user interface (GUI) that uses windows in a UNIX environment. The X Window System, also known as “X,” was developed jointly by the Massachusetts Institute of Technology (MIT), Stanford, and IBM starting in 1984, and its implementation is standardized by The Open Group. The X Window System is device-independent and provides a multitasking windowing environment for client computers.

The X Window System runs on network-attached workstations and terminals that access UNIX servers or mainframe computers. Elements of the X Window System include the following:

  • X servers, which form the server portion of the X Window System. These are typically UNIX servers but can also be mainframe computers running UNIX.
  • X clients, which are UNIX desktop workstations running the X Window System client software. The client software enables the workstations to display a windowed GUI in the X Window System environment. An alternative to using workstations is using X terminals, which are dumb terminals that have no operating system and use a ROM routine to implement X client software. X terminal machines must be connected to X servers by using local area network (LAN) connections, in contrast to character-based dumb terminals, which usually use serial connections such as RS-232 or X.21.
  • X protocol, the standard protocol for transmitting requests for windows functionality between X clients and X servers.
  • An X window manager, such as OSF/Motif, which implements windows features such as menus, toolbars, and gadgets that provide the look and feel of a windows GUI environment and allows X applications to run.