The compliance trope that a point-in-time-assessment can't be used to support a claim is kind of a lazy take. The certification explicitly states macOS v26.0 Tahoe.

While it's true that it wasn't always truly UNIX compliant, they put in the hard yards to become so (albeit to avoid a $200M lawsuit from The Open Group) [1]

[1] https://www.quora.com/What-goes-into-making-an-OS-to-be-Unix...

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p_ing 7 hours ago | parent [-]

To certify any version of macOS as UNIX, the security had to be significantly altered (disabling SIP) among a few other things. This is why what is shipped is not what is certified as UNIX. You can /make/ it match what is certified as an administrator, but that would be inadvisable.

https://www.osnews.com/story/141633/apples-macos-unix-certif...

EDIT: And really, UNIX certification means nothing except to potentially government agencies and people who don't understand what UNIX and/or UNIX certification is. Or why being "certified UNIX" is generally meaningless: see the BSDs, which are much closer to "UNIX" origins than macOS will ever be.

Or Windows, which is frankly just has better architected internals and abandons legacy UNIX ;-)

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rayiner 6 hours ago | parent | next [-]

> is. Or why being "certified UNIX" is generally meaningless: see the BSDs, which are much closer to "UNIX" origins than macOS will ever be

MacOS is BSD over Mach, which is itself derived from BSD.

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p_ing 6 hours ago | parent [-]

Yes, that's the point. It's further removed from UNIX than the BSDs are.

macOS contains BSD userland, networking, file system, POSIX, and a couple of other things. But XNU, the kernel, is "X is Not UNIX", if there ever was a statement to be made about the underpinnings of macOS.

https://developer.apple.com/library/archive/documentation/Da...

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inkyoto 2 hours ago | parent | next [-]

You have just described OSF/1 (and later – Tru64) – a certified UNIX with a hybrid kernel operating over a Mach microkernel, BSD userland, POSIX conformance etc.

What is the point that you are making?

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KerrAvon 4 hours ago | parent | prev | next [-]

This is a very silly argument.

There were several actual Unixes released based on Mach, and some of them more purely Mach than macOS/NeXT ever have been.

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sbuk 4 hours ago | parent | prev [-]

The people that certify it say that you are wrong. What you think and what actually is are two entirely different things in this case. The fact remains that, according to the OpenGroup (and they are the one that matter here), macOS 26 is UNIX.

	▲	p_ing 2 hours ago \| parent [-]
		macOS 26 that is /altered/ is UNIX. macOS that ships on every Mac is not certified UNIX -- but it can be made to match if you're willing to give up security. You should read through the actual certification - https://www.opengroup.org/csq/repository/noreferences=1&RID=... (there are a couple more in the repo). To run the VSX conformance test suite we first disable SIP as follows: [...] Feel free to disable SIP on your Mac. I certainly won't be doing so on mine.

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runjake 6 hours ago | parent | prev [-]

> Or Windows, which is frankly just has better architected internals and abandons legacy UNIX ;-)

Current macOS user, and former NT kernel dabbler and VMS user here. That's highly debatable.

On the kernel side, Windows is still filled with legacy VMS-isms. Eg: Object Manager (object/resource model), named objects, handles, how processes and threads work, vmem, scheduling etc etc

On the userspace side, Windows is still filled with legacy DOS-isms.

Don't me wrong, I love the underlying Windows OS, despite its many quirks, but it's filled with perhaps even more legacy cruft and definitely isn't any sort of step above anything else.

I also don't believe anyone actually runs macOS in a UNIX-compliant configuration. Rather, it's a checkbox on some RFP and nobody is clued into why it's actually there, because all the people that did know have since retired.

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p_ing 4 hours ago | parent [-]

What lineage of OS predates both DOS and VMS? :-)

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runjake 3 hours ago | parent [-]

As the popular phrase goes: "It's legacy, all the way down". What matters is what's left of those legacies in current revs.

In both cases: "Quite a bit", but I wish the base Windows OS would evolve away from legacy as much as macOS has. Start with eliminating drive letters.

	▲	p_ing 2 hours ago \| parent [-]
		> Start with eliminating drive letters. Drive letters are there for the presentation layer and of course backwards compat. Windows refers to them using device paths internally. You can too, if you wish. https://learn.microsoft.com/en-us/dotnet/standard/io/file-pa...