NT is not a derivative of OS/2 (although for a short period of time, before the complete break with IBM, MS was promoting it as vaporware OS/2 3.0 NT, for years in the future. I have an old issue of BYTE Magazine somewhere that showed it.). If NT was a derivative of OS/2, IBM would have had rights to it. Obviously, IBM never had access to any 32-bit OS product from Microsoft, and Microsoft chose not to ship any 32-bit OS/2, although some betas reportedly exist, as well as the IBM OS/2 2.0 PPC beta..
Actually, the OS/2 3.0 NT vaporware was turned into Windows NT. What actually happened is Microsoft and IBM Co-Designed OS/2 Version 1.0. They both had rights to create whatever they wanted on top and not license it to each other. For IBM to agree to this, Microsoft gave them a license to virtualize Win 3.x under OS/2 Then IBM created OS/2 2.0 based on 1.0 and MS created 3.0, also off of the 1.0 code-base, and then, when the disagreed with IBM ran with it, and IBM went and created their own 3.0, which became OS/2 Warp 4.0 and died out/.