Windows NT wasn't a new ground-up project. It's based on some OS/2 code and design. When IBM and MS fell out and divorced over the OS/2 project, there were 3 v

Windows NT wasn't a new ground-up project. It's based on some OS/2 code and design. When IBM and MS fell out and divorced over the OS/2 project, there were 3 versions of OS/2 underway: • OS/2 1, 16-bit, for the 80286 • OS/2 2, 32-bit, for the 80386 • OS/2 3, 32-bit, CPU-independent and cross-platform. IBM kept v2, finished it, and released OS/2 2, 2.1, 3, 4 & 4.5. V3 and after were codenamed "Warp" but the company failed to negotiate with the owners of Star Trek for a marketing deal. MS kept OS/2 3, the planned CPU-independent version. Dave Cutler and his team at DEC were angry at DEC management because DEC cancelled the Mica cross-platform OS and PRISM RISC CPU to run it. Cutler was head-hunted by MS and given OS/2 3 to finish and make work. The project was originally developed on the Intel i860 RISC chip, codenamed N10. (8086, 286, 386, 486 = X86. 86 * 10 = 860 = i860.) So it was called OS/2 NT for N-Ten. While work was underway, Windows 3 became a huge hit. The company worked out a 32-bit version of the Windows API, called Win32, and renamed OS/2 NT to "Windows NT". Yes, there is a lot of VMS design in the NT design, but it's not direct inheritance: it's because Cutler was planning a CPU-independent VMS with "personalities" that could run binaries from other OSes, such as DOS and UNIX. And aside from that, there is also a fair chunk of OS/2. NT 3.x could use OS/2 HPFS disk volumes, run text-mode OS/2 binaries, and had an optional extra Presentation Manager add-on to run graphical OS/2 binaries.