At least they invented and marketed OLE. The importance of this technology seems to be underestimated. OLE for windowed environments is the same as the streams/pipes philosophy in UNIX. In fact OLE/COM is something that's still missing in UNIX (and don't tell me about gtk which is a shitty and buggy piece of software).

From GUI perspective MS did a lot of things that X and MacOS "adopted" or tried to adopt silently, so to say.

After all, MS does hire talented staff. Just don't underestimate them.