[flomo]

Late reply, but

> VMS, which is not remotely UNIX-like

OpenVMS was UNIX-certified, so it's like UNIX enough to have the trademark.

Of course the UNIX stuff ran on top of the VMS stuff, and the early 1990s X11 stuff run on top of that. You can run CDE on Windows or Mac too, I don't see what's interesting about it.