What’s the general opinion on the BSDs? Are they just Unix-Like (like Linux), or are they really Unix?
Some call them “heritage Unix”, because, although they no longer contain a single line of AT&T code (and haven’t for over 40 years), they were ultimately derived from the original Unix.
This is a bit tongue-in-cheek, because I wonder, if you consider BSD to be “true Unix”, what other “Unix-like” operating system besides Linux kernel-based systems there are. Or are “real” Unices also considered “unix-like”?
As an aside, what about macOS, if you use the command line a lot?
The list of “certified” UNIXes is pretty limited. The referenced site only lists like 7 UNIX versions as certified and don’t mention FreeBSD, OpenBSD, NetBSD or DragonFlyBSD, just stuff like AIX, SCO, IBM z/OS and HP-UX in addition to macOS.