As AT&T contemplated its next major revision to Unix, which would eventually become SVR4, it was clear that in order to remain competitive with other operating systems, Unix should have a standard GUI definition. One other concern of the time also needed to be taken into account: in March 1988, Apple filed a lawsuit against Microsoft, claiming that Microsoft had copied the Macintosh look and feel.
The specification was a collaboration between Sun and AT&T, which were partnering in the development of SVR4. Xerox PARC was also credited for having not only done the pioneering work in the industry for graphical user interfaces, but also for contributing to OPEN LOOK's "design, review, implementation, testing, and refinement". Involving Xerox, including licensing technology from them, was felt to serve as protection from any future legal entanglements.
The OPEN LOOK specification was announced in April 1988. The following month, a group of competitors to AT&T and Sun formed the Open Software Foundation (OSF), as a counter to their collaborative efforts. The OSF created the Motif GUI as its alternative to OPEN LOOK.
It is a definition of a look and feel rather than a specific implementation, so it could actually be implemented with different programming toolkits or even on different underlying window systems—implementations were created for both the X Window System (X) and Sun's NeWS desktop environment.
Sun developed an X Window System distribution based on the OPEN LOOK look and feel, calling it OpenWindows. Its programming implementation for the OPEN LOOK look and feel was a choice of either the OPEN LOOK Intrinsics Toolkit (OLIT) or XView. The former was built on the Xt Intrinsics toolkit common to X; the latter used the same paradigm as the GUI libraries for Sun's earlier SunView window system, making it relatively easy to use it to migrate applications from SunView to X.
There was also The NeWS Toolkit, or TNT, which as the name implies implemented OPEN LOOK for NeWS applications; support for NeWS applications was removed from OpenWindows in 1993.
In 1990, Unix System Laboratories (USL) inherited OLIT from AT&T along with UNIX. Not long after, the codebase for OLIT diverged as Sun and USL took its development in different directions. Sun continued to enhance its version to make its look and feel more consistent with XView. USL, in an attempt to create an API to make applications GUI independent, developed the awkwardly named MoOLIT (from Motif OPEN LOOK Intrinsics Toolkit), which kept the OLIT API, but allowed users to choose which GUI they wanted at run time. The source to MoOLIT was licensed by MJM Software, who ported it to several other Unix platforms. It was used for several years, almost exclusively by AT&T and Lucent Technologies, who wanted to give their existing OPEN LOOK applications a Motif look and feel. It was not widely used elsewhere.
Sun began by offering the Motif developer toolkit and mwm window manager as a standalone product for use with Sun's Solaris Operating System until CDE was released in 1995. OpenWindows remained the primary Solaris desktop environment until 1997, when CDE became the primary desktop for Solaris 2.6. Even then, OpenWindows was still included with Solaris and could continue to be used instead of CDE.
When Solaris 9 was released in 2002, development support for XView and OLIT-based applications was finally removed, as were the olwm window manager and the OPEN LOOK versions of the DeskSet productivity tools.
Applications already developed using XView and OLIT can still be executed and displayed in both Solaris 9 and 10. There are also at least two projects continuing development of OpenWindows software: "OWAcomp" makes it possible to still use the OPEN LOOK Deskset tools, as well as compile OPEN LOOK applications; "openlook" is based on OpenWindows code released as open source, but has added additional components that were not open sourced by Sun.