Motif is a Graphical User Interface (as well as the widget toolkit) for Unix and Unix-like operating systems running the X Window System. It was first developed in the 1980s.

Motif uses a square, three-dimensional, chiseled appearance to draw interface windows, dialog boxes, and other GUI elements. Over the years, it was developed to closely mimic the popular Windows and OS/2 GUIs, with Microsoft contributing to Motif’s design style guide.

Motif was proprietary software until 2012, when its source was opened and licensed under the LGPL. Today, its source code is hosted on SourceForge.

Operating System terms, Window