Windows NT 3.1 was the first of the Windows NT series. Sporting the same face as its consumer counterpart Windows 3.1, it was completely different under the hood. A true 32-bit native operating system, Windows NT descended from the work Microsoft did while collaborating with IBM on OS/2 after the great split, and bringing in former DEC employees like Dave Cutler, bringing a VMS influence into the system. It was followed up by Windows NT 4.0.