I cannot possibly imagine how this could be true.
Linux is, legally, not Unix, and it is released under a license which does not discriminate based on who you are.
Linux is, legally, not Unix, and it is released under a license which does not discriminate based on who you are.
An awful lot has changed since then, including Microsoft buying a System V Unix license when SCO was extorting everyone (including Sun, as I recall) into doing that. There is so much water under the bridge, I imagine Microsoft could do it if they wanted to. But why?
I don't see how it's a good idea from their point of view. An ubuntu respin is about as far as I'd ever expect them to go down that path, and even that seems like more commitment than they'd want to make.
MS tends to keep a lot of fingers in a lot of cakes, even in surprising areas. Given the number of kernels MS Research has released, it wouldn't be too terrible of a stretch to see MS release some sort of unix at some point.
I think the big thing that would keep MSFT from rolling their own is fear of antitrust law, in the US and Europe. Less of a concern for them when it comes to Linux on phones or embedded, I believe.
From that article:
"according to AT&T, roughly half of the 500,000 Unix licenses are held by Xenix developers"
I really am amazed by that figure, though. Wow. And I had forgotten that xenix ran on some bigger machines, not just pcs.
They later bought Interix, who created the foundations of Windows Services For Unix, which was a much better and actually usable Unixlike layer, running directly as an NT subsystem, at the same level as Win32.
(This is as distinct from Cygwin, which supplies a GNU layer on top of Win32.)