CUA
was done by IBM, DEC, Sun, MSFT, and various other companies, though IBM had the major role (at the time, it was still the 800 pound gorilla, though the decline had already started). The idea was to create a standardized look'n'feel that would hold across these firms' GUI offerings, so that people could move from one to another with a minimum of fuss and bother.
The acme of the CUA desktop is the OS/2 desktop... part of the reason I know this about it, as I actually read the docs that came with my copy of Warp Connect lo these many years ago. There was a couple of pages devoted to CUA in (IIRC) the "Up and Running with OS/2 Warp" book that came with the system.
Docs were better in the old days.
