Tiling window manager

In computing, a tiling window manager is a window manager with an organization of the screen into mutually non-overlapping frames, as opposed to the more common approach (used by stacking window managers) of coordinate-based stacking of overlapping objects (windows) that tries to fully emulate the desktop metaphor. The first Xerox Star system (released in 1981) tiled application windows, but allowed dialogs and property windows to overlap. Later, Xerox PARC also developed CEDAR (released in 1982), the first windowing system using a tiled window manager. Next in 1983 came Andrew WM, a complete tiled windowing system later replaced by X11. Microsoft's Windows 1.0 (released in 1985) also used tiling (see sections below). In 1986 came Digital Research's GEM 2.0, a windowing system for the CP/M which used tiling by default. One of the early (created in 1988) tiling WMs was Siemens' RTL, up to today a textbook example because of its algorithms of automated window scaling, placement and arrangement, and (de)iconification. RTL ran on X11R2 and R3, mainly on the "native" Siemens systems, e.g., SINIX. Its features are described by its promotional video. The Andrew Project (AP or tAP) was a desktop client system (like early GNOME) for X with a tiling and overlapping window manager. MacOS X 10.11 El Capitan released in September 2015 introduces new window management features such as creating a full-screen split view limited to two app windows side-by-side in full screen by holding down the full-screen button in the upper-left corner of a window. The built-in Microsoft Windows window manager has, since Windows 2.0, followed the traditional stacking approach by default. It can also act as a rudimentary tiling window manager. To tile windows, the user selects them in the taskbar and uses the context menu choice Tile Vertically or Tile Horizontally. Choosing Tile Vertically will cause the windows to tile horizontally but take on a vertical shape, while choosing Tile Horizontally will cause the windows to tile vertically but take on a horizontal shape.