[pjmlp]

IBM and Unisys mainframes also support POSIX filesystems, as does Windows, so now they are UNIXes?

[monocasa]

z/OS is a full blown, certified UNIX. WSL1 makes NT a unix kernel if they wanted to get the certification.

And redox goes beyond them in that the only user mode env it supports is posix with some extensions.

But how is this line germane to the original point again? That somehow being a microkernel means that it can't be a unix like design OS?

[pjmlp]

Certified UNIX means having a userspace POSIX library, completely unrelated to kernel architectures.

So if Microsoft bothers to certify WSL2 then Windows is now UNIX?!?

[Koshkin]

What defines a “UNIX kernel” anyway?

[pjmlp]

Plenty of CS books explain it better than me on an HN comment.

[gpderetta]

> So if Microsoft bothers to certify WSL2 then Windows is now UNIX?!?

Of course, the WSL2 layer would be UNIX. There is more than it so calling Windows exclusively unix would be wrong (in the same way that running Windows under a VM, or Winde, on an unix system doesn't make it Windows.

[monocasa]

Since you ignored my question, I'll ask it again.

> But how is this line germane to the original point again? That somehow being a microkernel means that it can't be a unix like design OS?

[pjmlp]

Please provide an example of an UNIX descendant from Bell Labs implemented microkernel.

POSIX userspace doesn't count, by that measure even an Amiga OS is sundenly an UNIX kernel.

Also a reference CS book in UNIX microkernels architecture would be welcomed.

Even Tanebaum doesn't call Minix 3 a UNIX, rather UNIX inspired.

[monocasa]

Your original post says "UNIX style", not "UNIX descendent from Bell Labs". Don't shift goalposts.

[gpderetta]

OSF/1 counts I think.