DM (Display Manager) was the window system used by Apollo Computer Inc. for its Apollo/Domain line of workstations running the AEGIS operating system, and later Domain/OS. A windowing system (also windows system or window system) is a standard part of all modern computer graphical user interfaces, as opposed to command line interfaces. ... This article does not cite its references or sources. ... Apollo/Domain was a range of workstations developed and produced by Apollo Computers, Inc. ... Domain/OS was the operating system used by the Apollo/Domain line of workstations manufactured by Apollo Computers, Inc. ...