OSX is a thin layer of UNIX with a lot of non-UNIX like stuff. Aqua over X. Self-contained apps over package management (unless you want to count the app store).
I find it more like a broken borked *NIX system than anything.
Neither FreeBSD nor NetBSD have been submitted to the Open Group for certification, and are thus considered "Unix-like". When I say OSX is literally Unix, I mean it has passed certification and can legally use UNIX trademark.
I knew that, but I left it out because I don't consider it consumer-grade. It's not something you'd find on a PC you'd buy at Best Buy, Tiger Direct, Amazon, etc, nor is it something you'd give to a non technical user and expect them to use.
As long as you consider OSX to be a Linux distro (lol) with a Apple UI, then sure.
But I doubt Microsoft ever gets any closer to unix-like systems than Apple is.