Window manager
In the early 1980s, the Xerox Star, successor to the Alto, used tiling for most main application windows, and used overlapping only for dialogue boxes, removing most of the need for stacking.
[8] 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.
[11] During the mid-1980s, Amiga OS contained an early example of a compositing window manager called Intuition (one of the low-level libraries of AmigaOS, which was present in Amiga system 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.
The Amiga windowing system would then use a series of bit blits 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).
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 Workplace Shell that made its debut in OS/2 2.0.
Strictly speaking, an X window manager does not directly interact with video hardware, mice, or keyboards – that is the responsibility of the display server.
For example, a flash player application can be re-parented to a browser window, and can appear to the user as supposedly being part of that program.
Thereby, it is easily possible to e.g. have X Window System client programs running either in the same Cygwin environment on the same machine, or on a Linux, BSD Unix etc.
system via the network, and only their GUI being displayed and usable on top of the Microsoft Windows environment.
Note that Microsoft and X Window System use different terms to describe similar concepts.
For example, there is rarely any mention of the term window manager by Microsoft because it is integrated and non-replaceable, and distinct from the shell.
[clarification needed][16] The Windows Shell is analogous to the desktop environment concept in other graphical user interface systems.
One typical key combination is Alt+Tab, used by Windows and KDE (by default, though this is user-configurable); another is apple key-tilde, used by Macintosh.
Pressing the appropriate key combination typically cycles through all visible windows in some order, though other actions are possible.
Under X, the window manager and the display server are two distinct programs; but under Wayland, the function of both is handled by the Wayland compositor.
