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 originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at ...

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

that adopts all other windows. In the

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

root window In the X Window System, a window is the region of the screen where drawing can occur. The root window covers the entire screen surface. Every window created is contained within it, forming a hierarchy with the root window at the very top. All ot ...

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 decorations and title bars as well as allows advanced control over the windows' operation required, for example, by virtual window managers. Technically, a reparenting window manager registers with the

X server X server may refer to: * a display server for the X Window System * X.Org Server, the X.Org Foundation's display server for the X Window System * HPE Integrity Superdome X Server, a line of HPE Integrity Servers HPE Integrity Servers is a ser ...

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 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 loa ...

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 *