Window manager

A window manager is computer software that controls the placement and appearance of windows within a windowing system in a graphical user interface; they are typically associated with the X Window System (see X window manager), but 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.