A stacking window manager (also called floating window manager) is a

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 draws and allows windows to overlap, without using a compositing algorithm. All window managers that allow the overlapping of windows but are not

compositing window manager A compositing manager, or compositor, is software that provides applications with an off-screen data buffer, buffer for each window, then Compositing, composites these window buffers into an image representing the screen and writes the result into ...

s are considered stacking window managers, although it is possible that not all use exactly the same methods. Other window managers that are not considered stacking window managers are those that do not allow the overlapping of windows, which are called

tiling window manager In computing, a tiling window manager is a window manager with the organization of the screen often dependant on mathematical formulas to organise the windows into a non-overlapping frame. This is opposed to the more common approach used by stac ...

s. Stacking window managers allow windows to overlap using clipping to allow applications to write only to the visible parts of the windows they present. The order in which windows are to be stacked is called their z-order.

History

* 1970s: The

Xerox Alto The Xerox Alto is a computer system developed at Xerox PARC (Palo Alto Research Center) in the 1970s. It is considered one of the first workstations or personal computers, and its development pioneered many aspects of modern computing. It featu ...

which contained the first working commercial GUI used a stacking window manager. * Early 1980s: The

Xerox Star The Xerox Star workstation, officially named Xerox Star 8010 Information System, is the first commercial personal computer to incorporate technologies that have since become standard in personal computers, including a bitmapped display, a window- ...

, successor to the Alto, used tiling for most main application windows, and used overlapping only for dialogue windows removing the need for full stacking. * The

Classic Mac OS Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Mac (computer), Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and end ...

was one of the earliest commercially successful examples of a GUI which used stacking windows. * GEM predated Microsoft Windows and used stacking, allowing all windows to overlap. * Amiga OS contains an early example of a highly advanced stacking window manager.

Microsoft Windows

Microsoft Windows 1.0 displayed windows using a

. In Windows 2.0, it was replaced with a stacking window manager, which allowed windows to overlap. Microsoft kept the stacking window manager up through

Windows XP Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct successor to Windows 2000 for high-end and business users a ...

, which presented severe limitations to its ability to display 3D-accelerated content inside normal windows. Although it was technically possible to produce some visual effects using third-party software. From

Windows Vista Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, released five years earlier, which was then the longest time span between successive releases of Microsoft W ...

onward, a new

is the default on compatible systems.

X Window System

Many windows managers under the

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 ...

provide stacking window functionality: * 2bwm *

4Dwm IRIX (, ) is a discontinued operating system developed by Silicon Graphics (SGI) to run on the company's proprietary MIPS architecture, MIPS workstations and servers. It is based on UNIX System V with Berkeley Software Distribution, BSD extensio ...

AfterStep AfterStep is a stacking window manager for the X Window System. The goal of AfterStep's development is to provide for flexibility of desktop configuration, improved aesthetics and efficient use of system resources, and was used in such distributi ...

* amiwm * awesome * berry * Blackbox *

ctwm In Unix computing, CTWM (Claude's Tab Window Manager) is a stacking window manager for the X Window System in the twm family of window managers. CTWM was created in 1992 by Claude Lecommandeur of EPFL from the source code for twm, which he ex ...

* cwm * dwm * qpwm * eggwm * Enlightenment *

Fluxbox Fluxbox is a stacking window manager for the X Window System, which started as a fork of Blackbox 0.61.1 in 2001, with the same aim to be lightweight. Its user interface has only a taskbar, a pop-up menu accessible by right-clicking on the d ...

* FLWM * FrankenWM *

FVWM The F Virtual Window Manager (FVWM) is a virtual window manager for the X Window System. Originally a twm derivative, FVWM is now a window manager for Unix-like systems. History In 1993, during his work analyzing acoustic signatures for the ...

* FVWM95 * Goomwwm * Hackedbox *

IceWM IceWM is a stacking window manager for the X Window System, originally written by Marko Maček. It was written from scratch in C++ and is released under the terms of the GNU Lesser General Public License. It is customizable, relatively light ...

* Iwm * jbwm * JWM * Karmen *

KWin KWin is a window manager for the X Window System and a Wayland (display server protocol)#Wayland compositors, Wayland compositor. It is released as a part of KDE Plasma, for which it is the default window manager. KWin can also be used on its o ...

(with compositing turned off) * MLVWM * MWM * Mutter *

Muffin A muffin or bun is an individually portioned baked product; however, the term can refer to one of two distinct items: a part-raised flatbread (like a crumpet) that is baked and then cooked on a griddle (typically unsweetened), or a (often sw ...

* olwm * Openbox * pawm * PLWM *

Sawfish Sawfish, also known as carpenter sharks, are a family of very large rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the lar ...

* Scwm * swm * TinyWM * tvtwm *

twm twm (Tab Window Manager) is a window manager for the X Window System. Started in 1987 by Tom LaStrange, it has been the standard window manager for the X Window System since version X11R4. The name originally stood for Tom's Window Manager, but ...

* vwm * vtwm * Window Maker * WindowLab * wm2 * wmx

Hybrid window managers

Some window managers may be able to treat the foreground window in an entirely different way, by rendering it indirectly, and sending its output to the video card to be added to the outgoing raster. While this technique may be possible to accomplish within some stacking window managers, it is technically

compositing Compositing is the process or technique of combining visual elements from separate sources into single images, often to create the illusion that all those elements are parts of the same scene. Live action, Live-action shooting for compositing ...

, with the foreground window and the screen raster being treated the same way two windows would be in a

. Interacting with objects outside the original area of the foreground window might also be impossible, since the window manager would not be able to determine what the user is seeing, and would pass such mouse clicks to whatever programs occupied those areas of the screen during the last stacking event.

References

External links

Graphical User Interface Gallery
{{XWinSys Window managers X window managers