
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. In 1986 came Digital Research's GEM 2.0, a windowing system for the CP/M which used tiling by default. Microsoft's Windows 1.0 (released in 1985) also used tiling (see sections below). Next in 1983 came Andrew WM, a complete tiled windowing system later replaced by X11. Later, Xerox PARC also developed CEDAR (released in 1982), the first windowing system using a tiled window manager. The first Xerox Star system (released in 1981) tiled application windows, but allowed dialogs and property windows to overlap. 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 dwm window manager with the screen divided into four tiles.
