A re-parenting window manager is an

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting ...

window manager A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment. They work in conjunct ...

that adopts all other windows. In the

, every window has a parent window, which may be either the

root window {{Unreferenced, date=September 2008 In the X Window System, every window is contained within another window, called its parent. This makes the windows form a hierarchy. The root window is the root of this hierarchy. It is as large as the screen/di ...

or another window. Windows that are children of the root window are called ''top-level windows''. When a top-level window is created, a re-parenting window manager changes that window's parent to be a second new window created by the window manager for this purpose. This allows the window manager to decorate the windows with

window decoration In computing, a window is a Graphical widget, graphical control element. It consists of a visual area containing some of the graphical user interface of the program it belongs to and is framed by a #Window decoration, window decoration. It usuall ...

s and title bars as well as allows advanced control over the windows' operation required, for example, by

virtual window manager Virtual may refer to: * Virtual (horse), a thoroughbred racehorse * Virtual channel, a channel designation which differs from that of the actual radio channel (or range of frequencies) on which the signal travels * Virtual function, a programming ...

s. Technically, a reparenting window manager registers with the X server to be notified when a top-level window is mapped (attempts to become visible). When such an event is generated, the window manager creates a frame window, and in most cases also a title bar window. The frame window then becomes the parent of both the main window and the title bar window. Other forms of decoration, such as buttons, window title, etc., may also be created; these would normally be parented by the title bar window. Xlib Programming Manual Chapter 10
Virtually all modern window managers are re-parenting, although earlier window managers, such as the uwm window manager, were not. Exceptions to that rule are dwm, cwm, PLWM,

ratpoison ratpoison is a tiling window manager for the X Window System primarily developed by Shawn Betts. ratpoison is written in C; Betts' StumpWM re-implements a similar window manager in Common Lisp. The user interface and much of their functionalit ...

and xmonad, due to a lack of any typical window decorations used by these window managers, and also

Compiz Compiz () is a compositing window manager for the X Window System, using 3D graphics hardware to create fast compositing desktop effects for window management. Effects, such as a minimization animation or a cube workspace, are implemented as ...

which drew the decorations separately up until version 0.9.0, where it became a re-parenting window manager to allow it to run in a non-composited mode. Even though stumpwm does not draw typical window decorations, it reparents windows in a parent frame to display outlines.

References

{{XWinSys *