As I said go Async, I think there's two conversations going on in these threads: POSIX for UNIX portability; general portability. POSIX succeeded on prior but not latter as it wasnt designed for it. Today, we have portability frameworks that can do more than POSIX on more OS's. They definitely win on general portability with them worth consideration for UNIX portability. That's my position.
Far as early days, you might be able to help me out on a point I have few sources on. One history of Xenix posted here claimed its influence and design choices had strong influence on adoption of features that latter led to POSIX. Source was biased so hard to assess. What's your take on Xenix's influence on adoption of standard or POSIX-like API's?
I bet your source was right. I don't have inside knowledge, but as one of the first Unixes to try to make a serious business out of it, and as an arguable progenitor of the SysV approach, it wouldn't surprise me.
That said, POSIX was never designed for general portability. Just as a seal of unifying approval and sanity for existing practice; far more descriptive than prescriptive.
Far as early days, you might be able to help me out on a point I have few sources on. One history of Xenix posted here claimed its influence and design choices had strong influence on adoption of features that latter led to POSIX. Source was biased so hard to assess. What's your take on Xenix's influence on adoption of standard or POSIX-like API's?