Editing Window manager (section)

== History ==
{{Main article|History of the graphical user interface}}

In 1973, the [[Xerox Alto]] became the first computer shipped with a working [[WIMP (computing)|WIMP]] [[Graphical user interface|GUI]]. It used a [[stacking window manager]] that allowed overlapping windows.<ref>{{Cite web |author-first=Nathan |author-last=Lineback |url=http://toastytech.com/guis/alto3.html|title=The Xerox Alto|website=toastytech.com}}</ref> However, this was so far ahead of its time that its design paradigm would not become widely adopted until more than a decade later. While it is unclear if [[Microsoft Windows]] contains designs copied from Apple's [[classic Mac OS]], it is clear that neither was the first to produce a GUI using stacking windows. In the early 1980s, the [[Xerox Star]], successor to the Alto, used [[Tiling window manager|tiling]] for most main application windows, and used overlapping only for dialogue boxes, removing most of the need for stacking.<ref>{{Cite web |author-first=Nathan |author-last=Lineback |url=http://toastytech.com/guis/star.html|title=The Xerox Star|website=toastytech.com}}</ref>

The [[classic Mac OS]] was one of the earliest commercially successful examples of a GUI that used a sort of stacking window management via [[QuickDraw]]. Its successor, [[macOS]], uses a somewhat more advanced window manager that has supported compositing since [[Mac OS X 10.0]], and was updated in [[Mac OS X 10.2]] to support hardware accelerated compositing via the [[Quartz Compositor]].<ref name="quartz">{{Cite web|url=https://arstechnica.com/gadgets/2005/04/macosx-10-4/13/|title=Mac OS X 10.4: Quartz|first=John|last=Siracusa|date=28 April 2005|website=[[Ars Technica]]}}</ref>

[[GEM 1.1]], from [[Digital Research]], was a [[operating environment]] that included a stacking window manager, allowing all windows to overlap. It was released in the early 1980s.<ref name="Lineback_GEM11"/> [[GEM (desktop environment)|GEM]] is famous for having been included as the main GUI used on the [[Atari ST]], which ran [[Atari TOS]], and was also a popular GUI for [[MS-DOS]] prior to the widespread use of Microsoft Windows. As a result of a lawsuit by [[Apple Computer|Apple]], Digital Research was forced to remove the stacking capabilities in GEM 2.0, making its window manager a tiling window manager.<ref name="Lineback_GEM20"/>

During the mid-1980s, [[Amiga OS]] contained an early example of a compositing window manager called ''[[Intuition (Amiga)|Intuition]]'' (one of the low-level libraries of AmigaOS, which was present in Amiga system [[Read-only memory|ROMs]]), capable of recognizing which windows or portions of them were covered, and which windows were in the foreground and fully visible, so it could draw only parts of the screen that required refresh. Additionally, Intuition supported compositing. Applications could first request a region of memory outside the current display region for use as bitmap. The Amiga windowing system would then use a series of [[bit blit]]s using the system's hardware [[blitter]] to build a composite of these applications' bitmaps, along with buttons and sliders, in display memory, without requiring these applications to redraw any of their bitmaps.

In 1988, [[Presentation Manager]] became the default shell in [[OS/2]], which, in its first version, only used a [[command line interface]] (CLI). [[IBM]] and Microsoft designed OS/2 as a successor to DOS and Windows for DOS. After the success of Windows 3.10, however, Microsoft abandoned the project in favor of Windows. After that, the Microsoft project for a future OS/2 version 3 became [[Windows NT]], and IBM made a complete redesign of the shell of OS/2, substituting the Presentation Manager of OS/2 1.x for the [[Object-oriented user interface|object-oriented]] [[Workplace Shell]] that made its debut in OS/2 2.0.<ref>{{Cite web|url=http://www.os2bbs.com/OS2News/OS2History.html|title=OS/2 History|archive-url=https://web.archive.org/web/19980213061837/http://www.os2bbs.com/OS2News/OS2History.html|archive-date=13 February 1998}}</ref>