Editing X window manager

{{short description|Type of window manager}}
{{one source|date=November 2011}}
[[File:Schema of the layers of the graphical user interface.svg|thumb|300px|The [[windowing system]] based on the X11 protocol keeps [[display server]] and [[window manager]] as separate components.]]

An '''X window manager''' is a [[window manager]] that runs on top of the [[X Window System]], a windowing system mainly used on [[Unix-like]] systems.

Unlike [[classic Mac OS|MacOS Classic]], [[macOS]], and [[Microsoft Windows]] platforms (excepting Microsoft Windows [[explorer.exe]] [[Windows shell replacement|shell replacements]]), which have historically provided a vendor-controlled, fixed set of ways to control how windows and [[Paned window (computing)|pane]]s display on a [[Computer display|screen]], and how the user may interact with them, window management for the X Window System was deliberately kept separate from the software providing the graphical display. The user can choose between various third-party window managers, which differ from one another in several ways, including:

* customizability of appearance and functionality:
** textual [[Menu (computing)|menus]] used to start programs and/or change options
** [[Dock (computing)|docks]] and other graphical ways to start programs
** [[multiple desktops]] and [[virtual desktop]]s (desktops larger than the physical monitor size), and [[pager (GUI)|pagers]]<ref name="EWMH">{{Cite web|url=http://standards.freedesktop.org/wm-spec/wm-spec-latest.html#id2504750|title=Extended Window Manager Hints|website=standards.freedesktop.org|access-date=2018-09-16|archive-date=2008-02-25|archive-url=https://web.archive.org/web/20080225000427/http://standards.freedesktop.org/wm-spec/wm-spec-latest.html#id2504750|url-status=dead}}</ref> 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.

==How X window managers work==
When a window manager is running, some kinds of interaction between the [[X Window System protocols and architecture|X server]] and its [[X Window System protocols and architecture#The X client-server model and network transparency|clients]] are redirected through the window manager. In particular, whenever an attempt to show a new window is made, this request is redirected to the window manager, which decides the initial position of the window. Additionally, most modern window managers are [[Re-parenting window manager|reparenting]], which usually leads to a banner being placed at the top of the window and a decorative frame being drawn around the window. These two elements are controlled by the window manager rather than the program. Therefore, when the user clicks or drags these elements, it is the window manager that takes the appropriate actions (such as moving or resizing the window).

Window managers are also responsible for [[Icon (computing)|icon]]s. Indeed, icons do not exist at the [[X Window System core protocol]] level. When the user requests a window to be iconified, the window manager unmaps it (makes it non-visible) and takes the appropriate actions to show an icon in its place. Most modern window managers do not literally show icons to represent iconified windows anymore.  Often, an auxiliary toolbar program will allow access to iconified windows.

While the main aim of a window manager is to manage the windows, many window managers have additional features such as handling mouse clicks in the [[root window]], presenting panes and other visual elements, handling some keystrokes (e.g., Alt-F4 may close a window), deciding which application to run at start-up, etc.

Standardized protocols exist to allow normal clients to communicate with the window manager.  The original one is [[Inter-Client Communication Conventions Manual]] (ICCCM) but this has been superseded by the [[Extended Window Manager Hints]] (EWMH). These protocols allow clients to request titles for windows and icons, check if a window is iconified which might be docked or minimized, and possibly customize windows decorations, what [[virtual desktop]] the window occupies.<ref name="EWMH" /> Additional information from the window manager is available through the core protocol including the visibility of windows such as if a window is hidden on a different [[Virtual desktop]], and figuring out the adjustments for the window manager frames.{{Citation needed|date=September 2018}}

==Types of window managers==

===Stacking window managers===
{{Main|Stacking window manager}}

A '''stacking window manager''' renders the windows one-by-one onto the screen at specific co-ordinates. If one window's area overlaps another, then the window "on top" overwrites part of the other's visible appearance. This results in the appearance familiar to many users in which windows act a little bit like pieces of paper on a desktop, which can be moved around and allowed to overlap.

In contrast to ''compositing'' window managers (see below), the lack of separate [[off-screen buffer]]s can mean increased efficiency, but effects such as translucency are not possible.

Stacking window managers include [[Amiwm]], [[Blackbox]], [[CTWM]], [[Enlightenment (window manager)|Enlightenment]], [[Fluxbox]], [[FLWM]], [[FVWM]], [[IceWM]], [[Motif Window Manager|MWM]], [[Openbox]], [[Twm|TWM]] and [[Window Maker]].

===Tiling window managers===
{{Main|Tiling window manager}}

A '''tiling window manager''' is a window manager with an organization of the screen into mutually non-overlapping frames (hence the name [[tessellation|tiling]]), as opposed to the traditional approach of coordinate-based stacking of objects (windows) that tries to emulate the desk paradigm.

Tiling window managers include [[Awesome (window manager)|awesome]], [[dwm]], [[Ion (window manager)|ion]], [[larswm]], [[ratpoison]], [[Stumpwm]], [[wmii]], [[I3 (window manager)|i3]], [[xmonad]], and [[XWEM]].

===Compositing window managers===
{{Main|Compositing window manager}}

A '''compositing window manager''' may appear to the user similar to a stacking window manager. However, the individual windows are first rendered in individual buffers, and then their images are composited onto the screen buffer; this two-step process means that visual effects (such as shadows, translucency) can be applied. It also means that compositing window managers are inherently more resource-hungry than an equivalently-powerful stacking window manager. For this reason, some window managers for X do not support compositing by default, such as [[Openbox]].[http://askubuntu.com/questions/53745/compositing-in-lubuntu Compositing in Lubuntu]

[[Compositing window manager#History|Historically]], the Amiga in 1985, OSX in 2001, Java Looking Glass in 2003, and the Windows Longhorn demo in 2003 (delayed until Vista in 2007) preceded compositing efforts under X11.  Compositing window managers for X include:
* [[GNOME]]'s [[Mutter (window manager)|Mutter]] née [[Metacity]] (first dev-branch compositor in 2.7{{citation needed|date=September 2013}} or 2.8 [https://web.archive.org/web/20140607010531/http://webapp5.rrz.uni-hamburg.de/SuSe-Dokumentation/packages/metacity/NEWS Wayback Machine] of 2004 [http://www.linuxtoday.com/developer/2004083101126NWGNRL Linux Today - Release Digest: GNOME, August 30, 2004]—original stable-branch compositor since 2.14 in 2005 [https://mail.gnome.org/archives/metacity-devel-list/2005-November/msg00063.html Re: About Compositing] or 2006 [https://mail.gnome.org/archives/metacity-devel-list/2006-February/msg00011.html Metacity branched for 2.14]—current compositor architecture since 2.22 [http://tombuntu.com/index.php/2008/03/31/enable-metacity-compositing-in-gnome-222 Enable Metacity Compositing in GNOME 2.22 | Tombuntu] in 2008—Metacity+Clutter begat [[Mutter (window manager)|Mutter]] in 2011),
* [[Xfce]]'s [[Xfwm]] (since 4.2 of 2004{{citation needed|date=September 2013}} or 2005 [https://web.archive.org/web/20150923235500/https://mail.xfce.org/pipermail/xfce/2005-January/012328.html Xfce 4.2.0 released!]),
* [[Unity (user interface)|Unity]]'s [[Compiz]] (since 2005—was forked as [[Beryl (window manager)|Beryl]] in 2006 but the projects re-merged in 2007), and
* [[KDE]]'s [[KWin]] (since 4.0 of 2008).
Compositing support can be added to non-compositing window managers, through the use of compositors such as ''compton''.

===Virtual window managers===
A '''virtual window manager''' is a window manager that uses virtual screens, whose resolution can be higher than the resolution of one's monitor/[[display adapter]] thus resembling a two dimensional [[virtual desktop]] with its [[viewport]].  This environment is very useful when one wishes to have a large number of windows open at the same time.  A number of virtual window managers have been made, including [[FVWM]], [[Tvtwm]], [[HaZe]]<ref>{{cite web |title=HaZe - a real B&W; window manager |url=http://geocities.com/hazewm/ |website=HaZe Homepage |access-date=2024-08-31 |archive-date=2009-10-26 |archive-url=https://web.archive.org/web/20091026234522/http://geocities.com/hazewm/ |url-status=bot: unknown }}</ref> and others.

===Extensible window managers===
{{Category see also|X window managers extensible by scripting}}
Some window managers are extensible, or programmable, by user scripts.

In these window managers, users can define new actions or override the default, or reactions to various events, like window size and position changes, window creation and deletion, key and mouse input, timer, etc. They often provide on-the-fly code execution, too.

Some examples of such window managers and the used languages are:
* [[Awesome (window manager)|Awesome]] - [[Lua (programming language)|Lua]]<ref>{{Cite web|url=https://awesomewm.org/|title=home|website=awesome window manager|access-date=2022-07-27|archive-date=2007-10-11|archive-url=https://web.archive.org/web/20071011225622/http://awesome.naquadah.org/|url-status=live}}</ref>
* [[KWin]] - [[ECMAScript]]
* [[Qtile]] - [[Python (programming language)|Python]]
* [[Sawfish (window manager)|Sawfish]] - "rep", a [[lisp (programming language)|Lisp]] dialect
* [[Xmonad]] - [[haskell (programming language)|haskell]]
* [[StumpWM]] - [[Common Lisp]]
* [[GWM (window manager)|GWM]] - "WOOL", a Lisp dialect
* Bspwm - [[C (programming language)|C]]

==See also==
* [[Comparison of X window managers]]
* [[Re-parenting window manager]] for a popular implementation technique
* [[X Window System protocols and architecture]] for context
* [[Windowing system]]
* [[Wmctrl]] - a command-line utility used to control windows in EWMH and NetWM compatible window managers
* [[xdotool]] - another command-line utility used to control windows
* [[Wayland compositor]]

==References==
{{reflist}}

==External links==
* [https://www.gilesorr.com/wm/table.html ''The Comprehensive List of Window Managers for Unix'']
* [https://wiki.archlinux.org/index.php/Window_manager#List_of_window_managers ''ArchWiki List of Window Managers for Linux'']

{{XWinSys}}
{{X desktop environments and window managers}}

{{DEFAULTSORT:X Window Manager}}
[[Category:X window managers| ]]
[[Category:X Window System]]
[[Category:Graphical user interfaces]]