[conservatism_IS_compassion]

When Steve Jobs returned to Apple after the NeXT acquisition, very little of the NeXT technology came with him. One thing that did, though, was the NeXTSTEP operating system, built on the Mach kernal. Mach wasn't Unix (nor was it Linux), but it contained pieces gleaned from BSD and was a very Unix-like platform. Mach is still the basis of OS X as it continues to evolve.

And yet we know that, as of Leopard, OS X is Unix™.

[Swordmaker]

And yet we know that, as of Leopard, OS X is Unix™.

You are absolutely correct. In fact, it always was, just not certified. I thought about commenting on that on the article. . .