Workplace Shell

The Workplace Shell was an object-oriented desktop shell produced by IBM's Boca Raton development lab for OS/2 2.0. It was a radical shift away from the Program Manager type interface that earlier versions of OS/2 shared with Windows 3.x.

Workplace Shell objects were mostly written in C, glued together with an interface definition language called "SOM" (short for System Object Model), developed by IBM in their Austin, TX lab.

These objects were shipped in DLL form, and could then be acted on by the user or other programs as if they were true objects, although one could dispute whether the SOM paradigm was close enough.

An interesting part of the WPS design allowed for the developer of a class Y which extended a class X to execute an API which would go through the desktop and 'replace' all instances of class X with instances of class Y; i.e., almost a retroactive inheritance. This allowed for many useful desktop utilities that added functionality to existing objects (usually folders).