It has been optional because you have to pay for it. POSIX compliance has a cost associated with it. Not that I think POSIX compliance has any value anymore, mind you. I was replying to someone for whom POSIX compliance was a make or break feature.
Anyway, I sense an argument drift from "Windows" to "Modern Windows". Nice. I guess earlier versions of Windows stopped being Windows once version 8.1 was released.
> I guess earlier versions of Windows stopped being Windows once version 8.1 was released.
Well, yeah. We're (presumably) talking about software architecture choices here. Are you telling me you'd purposefully build a new system on top of an old version of Windows, and specifically on old features that have since been deprecated+removed? If not, then it doesn't matter what old Windows does; "Windows is not POSIX-compliant" is the fact that you are making a choice based upon when you design a system right now.
POSIX compliance (which probably only serves as a checkbox for some arcane procurement guideline) is only relevant in niche markets. You are trying to apply a general software design thought process which unfortunately doesn't work there. People still ship WinCE and '95 software. Software targeting old UNIX systems is still being written today.
BTW, I can purchase a copy of windows 8 today (which is going to be supported by Microsoft till 2023) that is POSIX compliant. So the argument is moot anyway.
Could you elaborate? In what I've learned (in the past few minutes) it looks like it hasn't has POSIX compatibility since an optional subsystem up to Windows 2000.
https://en.wikipedia.org/wiki/POSIX#POSIX_for_Windows
Elaborate on what? You have to purchase a version of Windows that has the POSIX layer because POSIX compliance costs money. From what I gather it has been dropped in Windows 8.1.
