X Window System

The X Window system, or X, or X11:

• Manages some hardware:
  • graphics/video cards,
  • keyboard and mouse.

  X enables text copy&paste with the mouse: select text using the left button, and copy it elsewhere with the middle button.

• Manages the display of applications in windows.

• Client Server system: a X server on a machine can display a client application running on another machine.

  An application server can run a client application for many machines with an X server (e.g. OpenOffice.org).