Re: Nice for abandonware
I think Microsoft started its version numbering for Windows NT with 3.1 because that was the same version number of the Windows desktop OS at the time. Both desktop and server OS largely shared the same GUI interface.
I remember installing Windows NT 3.1 from floppies for one of my college professors. Due to lack of software support, it wasn't exactly dazzling. It did offer a TCP/IP stack, a trick that took Novell a few (fateful) years to replicate
The software that was released as Windows NT was started [pre divorce] as OS/2 NT - the 'portable' version of OS/2, written in C instead of assembler. It also had a kernel + API design [Win32, Win16, OS/2 1.x, POSIX subset]
From what I recall, NetWare 3.x was introduced a couple of years before WinNT - and had several pluggable network protocols - both TCP/IP and IPX were available, but IPX was easier to configure.