On Thu, May 10, 2018 at 4:59 PM, Grant Taylor via TUHS <tuhs@minnie.tuhs.org> wrote:

Very well said Clem.

Linux is not Unix.
Linux is unix.

Linux is not UNIX.

According to the UNIX trademark guidelines, the second one is not permitted... :)

Note the case difference.

Linux does not have the licensing to claim to be a proper Unix (clone) and thus the privilege to use the uppercase "U". But (IMHO) Linux is very much in the unix spirit or idea.

There were a couple of very specific distributions of Linux that passed the Unix licensing tests from the X/Open group years ago, but I don't know what happened after that.

Analogy: A Toyota Tacoma is not a Ford Ranger (Unix) but they are both pickup trucks (unix).

I was going to say that Linux is a UNIX-like operating system, but The Open Group doesn't like that either :)

Warner