Re: "running as a native Ubuntu binary on a Windows subsystem"
NT 3.1 to NT 4.0 (and maybe later) had five subsystems:
1) NTVDM: Run dos programs in virtual machine, even x86 on Alpha, MIPS, PowerPC etc. Today not as good as "Dosbox" a cross platform emulator that could even run DOS graphical adventure games on Symbian. Works well on Windows and Linux)
2) WOW: Translate 16 bit Windows API calls to 32bit NT calls and probably runs the code in an NTVDM?
3) POSIX: Usually off. Sort of UNIX compatibility, you needed Internix or Services For Unix to really make use of it
4) Networking used essentially MS LanManager, which was option on pre Warp IBM OS/2 and bundled with pre 1993 MS OS/2 (briefly sold as server by MS for Wn3.x workstations to schools mostly), when IBM and MS parted company on OS/2
5) OS/2: OS/2 text mode (not Presentation Manager), i.e. Console apps ran perfectly on NT4.0 as I had to put some for an Accounts Dept.
I think Ballmer depreciated all this stuff. Mostly gone by Vista?
NT was originally very modular and before NT4.0 even Graphics (Screen & Printer) drivers sensible outside Kernel. NT 3.1 was first version in 1993, possibly because partly based on MS OS/2? As well as all Dave Cutler's VMS inspired work.
With Win95 MS started to lose the plot. They totally lost it in 2003 and the development for Vista went out of control, as well as the Ribbon inflicted on Office. Was XP, Server 2003*, Visual Studio 6, SQL7 and Office 2003 the peak of MS implementations?
[*Though I preferred Win2K Enterprise / Advance Server to Server 2003, it was a bit bloated, so we switched to Linux servers only in 2007]