NT 4.0 also came in Server, Terminal Server and Embedded editions. In the time since its initial release, Windows NT morphed to become Windows Server.
As an anniversary page for the operating system that Microsoft made available today notes, the server team added Active Directory, Group Policy, .NET support and more to what debuted as the NT core. The 2003 R2 Server release, released in 2005, provided the foundation for Microsoft to build Azure, Microsoft's cloud operating system.
I have (somewhat) fond memories of NT 4, as it was the operating system that helped launched my career as a full-time Microsoft watcher at PCWeek (now eWeek). I started at PCWeek as a dedicated Unix reporter back in the day. When the former Microsoft reporter there left, I was drafted for that job because (as my editor suggested at the time), "NT is pretty much like Unix" (I guess because both were primarily server operating systems?)