A lot of the BSD that's in OSX actually predates either FreeBSD or NetBSD, coming via NeXTStep from BSD 4.3 and via Mac OS X Server from 4.4. In addition there are FreeBSD influences. NetBSD seems largely independent.
Yeah, I saw that line and didn't know whether that was a connection or not (that's why I used some weasel words to hedge).
Looking at it more closely, it does look like a connection, but I think it is a fairly minor one. The first Mac OS X Server was still pretty close to NeXTStep/Rhapsody.
The bigger changes came later with Mac OS X, which was a major rewrite.
http://upload.wikimedia.org/wikipedia/commons/5/50/Unix_hist...
A lot of the BSD that's in OSX actually predates either FreeBSD or NetBSD, coming via NeXTStep from BSD 4.3 and via Mac OS X Server from 4.4. In addition there are FreeBSD influences. NetBSD seems largely independent.
That's also roughly what I remember (ex-NeXTie).