Linux is not Unix: it is not derived from AT&T Unix.
Linux 2.2 or 2.4 or so (possibly only Suse Linux) even had a kernel startup message "Unix compliance testing by UNIFIX" or something, back when Unix was considered more prestigious than Linux. It is / was by some official definition "a Unix", though not "UNIX the trademark by AT&T".
I’m fairly certain they’re referring to POSIX compatibility, not calling a Linux a Unix.
Oh damn, you are probably right.
By that definition, nor is BSD. It's kind of their whole raison d'étre.
BSD was originally a derivative of AT&T Unix.
You should read some BSD history.
Still originally a derivative of AT&T Unix. :)
What are the differences? I think of both as Unix-type sytems with macrokernels. I have no practical experience with BSDs.
Jeez, care to reply instead of downvoting? I would really like to know. I do keep an eye on the BSDs as a good example in some areas where Linux is bad.
Didn't downvote. But if you don't know the difference, then you seemed pretty confident in describing their differences.
BSDs are an actual fork of UNIX from the 90s. Linux is a kernel whose code is not forked from UNIX. The userland is most often GNU, which stands for GNU's Not Unix.
That's not an architectural difference though. The way that the systems are technically structured seems very, very similar to me. There are quality differences (BSD generally better) and feature and performance differences (Linux generally better), but not basic approach differences - is that wrong?