It has been said that WNT== V++ M++ S++
From what I remember NT design was inspired by the VMS design in the same way the BSD design was inspired by UNIX. Similar but not the same.
I heard a lot of the structures are very similar and contain very similar fields. Different enough to avoid being sued but functionally very much the same, of course that was a long time ago in the NT3.1 days.
I do claim that it was influenced by a lot of OSes and not solely or mainly by VMS as I got the impression some people tried to claim that. What I wanted to say is that you can easily write a similar story of proofing Windows NT is heavily influenced by UNIX.
Well yeah, but UNIX was heavily influenced by operating systems that came before it too.
Windows NT was basically VMS made to look like Windows 3.1 & MSDOS. So it had some influence from CP/M. I can't think of anything that went from UNIX straight into Windows NT. MSDOS had pipes, which might have come from UNIX (although in MSDOS the programs were run sequentially as there was no multitasking). MSDOS also had a built in \dev\ directory that could be used with devices (\dev\nul for example could be used instead of nul:
I'd love to see a write up of how UNIX heavily influenced Windows NT.
Windows NT was originally going to be a version of OS/2, it even supported text mode OS/2 software and the OS/2 file system for many years. So I imagine there is also some of IBM's operating systems as an influence too.