Excuse my ignorance, but what is the main advantages for getting your operating system certified for SUSV3 or V4, POSIX, or other UNIX spec? Is there really a distinct advantage to complying to the UNIX spec and getting certified as a UNIX system?
UNIX is extremely old, and major OS devs like Linux, Google Android and Microsoft Windows don’t use UNIX.
What’s the big advantage of Apple paying the hefty price for UNIX certification, and not the LINUX spec, which would enable much more application compatibility?
How does UNIX help if you
- Are a major OS developer? (MS, APL, etc)
- Indie/part of an open source project? (Linux distros, etc)
Unix specifications are standards.
Being “certified” for compliance shows that your software/operating system can work with software that requires conformance to that specific standard, not just claiming to do so.
This ultimately saves time for developers, as they don’t need to figure out if there are any quirks or missing features in your implementation of a particular standard in order to port a program to your platform.
what is the main advantages for getting your operating system certified for SUSV3 or V4, POSIX, or other UNIX spec?
These are the only viable de jure specs we have.
UNIX is extremely old
So is internal combustion. That doesn’t mean we don’t set standards for automobiles, though.
the LINUX spec, which would enable much more application compatibility?
What makes you think there is a “Linux spec”?
Do you mean the one where the OS boots from
/etc/init.d, or the one where systemd controls all that?
How about the user interface? Which desktop manager shall we specify, if any? GNOME, KDE, XFCE, WindowMaker…?
What, to be brief, does “Linux” mean to you, and why do you believe you have a right to insist that others define Linux the same way?
That’s why we have independent standards organizations. We require an arbiter to settle fights like this.
As it happens, there is a “Linux spec,” of sorts, in the LSB, but it’s far from complete, and owes a lot to the likes of POSIX and SUS.
How does UNIX help if you are a major OS developer?
It sets the goalposts. You know when you are done. If a user wants the OS to do something in conflict with the spec, you can say, “Sorry, we obey the spec.”
Indie/part of an open source project? (Linux distros, etc)
The Linux man pages are derived from the POSIX specs. (Source.) Since those man pages document what Linux does, that puts pressure on the maintainers of the documented interfaces to maintain POSIX compatibility.
I guess you’re too young to have lived through the Unix wars. Trust me, we don’t want to go back to those days.