And now we see just how confused this discussion is. It's conflating a bunch of concepts via a historically weighted analogy, which itself has a lot of baggage at this point.
I'd consider what's on top the more cathedraly part. It has the consistency in design and implementations. Merging FreeBSD with Mach might have been centralized developers looking for good results but actual results seem a bit more bazaar. QNX was the older cathedral of mixing UNIX and microkernels with good design + performance. There were others but it stands out.
> macos (nee osx) is the result of combining freebsd and the mach kernel, both very cathedraly technologies.
Not to mention the remains of NextStep. Also very Cacthedraly.
Edit: thinking about it, I wonder why Apple didn't keep using that name/brand. It's obviously there all over the API. Was the NextStep name/brand tainted as a doomed technology at the time?
