What does it say about the practical usefulness of this Windows facility that MS has, it seems, never maintained one of these 'personalities' long-term?
There was a lot in the air in the early 90's when Windows NT was born - it wasn't a given that Windows, Intel, or heck even TCP/IP were going to be the tech mainstays they are today. So the whole "subsystem" thing is part of some seriously good long term strategic planning, though you know it was defintely to have one foot out of the door if their partnership with IBM went south, which it did.
> What does it say about the practical usefulness of this Windows facility that MS has, it seems, never maintained one of these 'personalities' long-term?
I am no defender of MICROS~1 but I think this is a misrepresentation.
1. Win32 is an NT personality and it is still actively maintained after 31 years.
2. Win16 ran on NTVDM which arguably is tantamount to a personality, and that is still present and works in Windows 10 32-bit today.
3. Downvotes or not, I stand by my point: the original POSIX personality became Windows Services for Unix, which went through 4 releases: 1.0, 2.0, 3.0, and 3.5.
But WSU was effectively a proprietary x86-32 Unix. Those are all dead and gone now, Xinuos notwithstanding, and having such a tool is no use in C21.
So, it was axed 20Y ago. 12Y later it was replaced by WSL.
WSL 1 was replaced by WSL2, and I mourn its lost potential. I feel WSL1 should have become a proper NT personality, which would have resulted in some improvements to Windows' capabilities.
My question was genuine, not just rhetorical. I appreciate the additional context here, especially that Win32 is implemented as a long-lived NT personality. It's indeed a bummer that Microsoft didn't see it as expedient to maintain the others or continue to grow WSL1.
Windows Services for Unix was also longer-lived than I'd realized. Was that just before its time or did it have some other problem?
I think it's probably business case and revenue potential, not practical usefulness. I felt like Interix was plenty useful but probably couldn't earn its keep. I think that pluggable personalities even exists in NT speaks to the general Microsoft embrace / extend / extinguish methodology. They were a means to an end to win contracts.
