Editing X window manager (section)

===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''.