OPEN LOOK and Motif are two graphical user interfaces (GUIs). OPEN LOOK was
developed by Sun with help from AT&T and many industry reviewers; Motif was
developed by the Open Software Foundation (OSF) with input from many OSF
members.

OPEN LOOK is primarily a user-interface specification and style-guide; there
are several toolkits which can be used to produce OPEN LOOK applications.
Motif includes an API specification; the only sanctioned Motif toolkit is the
one from OSF. However, there are other toolkits which can be used to produce
programs which look and behave like OSF/Motif; one of these, Pure's (formerly
ParcPlace's; formerly Solbourne's) OI, is a "virtual toolkit" which provides
objects in the style of OPEN LOOK and Motif, at the user's choice.

OPEN LOOK GUI is also the name of a product from AT&T, comprising their OPEN
LOOK Intrinsics Toolkit and a variety of applications.

[Thanks to Ian Darwin, ian@sq.com, 5/91]

With the recent COSE announcement it appears that Sun will be phasing out
support for OPEN LOOK in favor of Motif.