I do not know if emulated VMS counts. At least until recently what was left of DEC was coming up with new releases. Our last VAX died about 6 months ago.
AIX is (or was) quite proprietary for IBM RS/6000 workstations, most of which actually had POWER processors rather than PowerPC processors. (Almost but not quite the same). I haven't actually logged on in a couple of years, as we replaced most of our AIX machines with Solaris machines about 6 years ago.
The digital Unix was on alpha stations and I think VAXen, but that was a few years back in Belgium, so I do not have any screen shots. The last time I was there it may have been Tru60, but the earlier times it was just called digital unix. Its WM seemd to be emulating the VMS look and feel.
OS/32 ran on Concurrant (and earlier Perkin-Elmer) mini-computers. For the most part it was a strictly green screen OS. As far as I know they never added any windowing to it at all. OS/32 was mostly developed for data acquisition. Even the multi-hundred MHz UltraSPARCS aren't as good at taking in data and throwing it to tape.