Motif (widget toolkit)
Motif refers to both a graphical user interface (GUI) specification and the widget toolkit for building applications that follow that specification under the X Window System on Unix and other POSIX-compliant systems. It emerged in the 1980s as Unix workstations were on the rise, as a competitor to the OPEN LOOK GUI. It is now the basic building block of the Common Desktop Environment. The IEEE 1295 standard defines the Motif API. As of version 2.1 Motif supports Unicode, which has made it widely used in several multilingual environments. The Motif look and feel is distinguished by its use of square, chiseled, three-dimensional effects for its various user interface elements — menus, buttons, sliders, text boxes, and the like. Motif's operation was designed to correspond closely with the then-familiar Microsoft Windows and OS/2's Presentation Manager interfaces, and Microsoft played a key role in designing the original style guide. Motif was created by the Open Software Foundation (and was sometimes even called OSF/Motif), which has now been subsumed by The Open Group. There are a few implementations of the Motif API. Motif the toolkit is the first. There is also Open Motif which is a release of the "original" Motif under more liberal licensing terms. Finally, the LessTif project aims to implement the API under the LGPL license.
Motif Window Manager
A plain text file is used to generate a root menu that the user can customize. Another plain text file controls the colors of MWM's GUI but little else. Motif and MWM were created by the Open Software Foundation (Motif was sometimes even called OSF/Motif) but is nowadays owned by The Open Group. Originally, MWM and Motif could only be purchased but now there is also Open Motif which is a release of the "original" Motif under more liberal licensing terms (though still not quite open source/free software). Also, the LessTif project has been working hard to implement the Motif API under the LGPL license. The project includes a clone of MWM with support for virtual desktops.