MacX isn't OSF compliant. It's based on X11 Release 4 Window System
Protocols; it has nothing to do with OSF or UNIX International's UNIX
standards. OSF (Open Software Foundation) and UNIX International are two
major UNIX organizations trying to set their standards for the UNIX
industry; they aren't particularly discussing X Windows. The X Consortium
is the one that defines and sets all the standards for X Window system.
Apple is a member of all three organizations.
MOTIF is an X Window Manager, developed by OSF. (It follows X protocols of
course.) The product is sometimes called MOTIF/OSF, since it's an OSF
product. ICS (Integrated Computer Solutions) is a company that ported in
the MOTIF Window Manager for A/UX.
On AppleLink, you can find contact information for the various vendors by
clicking the Library Index button to view the folder structure in the Tech
Info Library. An alphabetic listing of vendors is in the Third Party
Company Directory folder.