Yeah I hear this statement a lot too but macos is based on nextstep much more than it was on FreeBSD.

Of course nextstep borrowed some userland from FreeBSD and I think this is where the confusion originates. The actual kernel is totally different though.

Eh, sort of. NextStep was more 4.4BSD based. MacOS trasitioned to FreeBSD elements.

And the kernel space for both absolutely have a lot of BSD code, more than the Mach or IO/Kit portions last time I checked.

And I think the userland got a bit of a refresh from current FreeBSD when OS-X came out.