A window manager is software that controls the placement and appearance of application windows under the X Window System, a graphical user interface on Unix systems that enables a user to interact with a number of application programs simultaneously. Each one typically has its own independent window, and when a window manager is available, interaction between X Window display servers and their clients is redirected through the window manager.

This is unlike the Microsoft Windows and Apple Macintosh platforms, which have historically provided a vendor-controlled, fixed set of ways to control how windows and panes display on a screen, and how the user may interact with them. However, the X Window System allows the user to choose between various window managers to achieve different behavior from the program windows. Window managers differ from one another in several ways, including:

  • customizability of appearance and functionality:
    • textual menus used to start programs and/or change options
    • docks and other graphical ways to start programs
    • multiple desktops and virtual desktops (desktops larger than the physical monitor size), and pagers to switch between them
  • consumption of memory and other system resources
  • degree of integration with a desktop environment, which provides a more complete interface to the operating system, and provides a range of integrated utilities and applications.

A variety of window managers currently work under X, ranging from the bare-bones TWM (the very first window manager) to the rather elaborate Enlightenment.

Alternative shells for Microsoft Windows have also emerged. For example, LiteStep can replace the user interface on Windows 95, 98, or NT with an Afterstep style. OS/2 ships with Presentation Manager as the default shell, but third party sources can supply alternatives.

Table of contents
1 Popular window managers
2 Other window managers
3 External link

Popular window managers

Other window managers

External link