Comment by alexjplant

They didn't convince anybody of anything. They poured an enormous amount of technical work [1] into making it compliant with the Single Unix Specification [2].

> The standard specifies programming interfaces for the C language, a command-line shell, and user commands.

What else would be necessary to call it such?

[1] https://www.quora.com/What-goes-into-making-an-OS-to-be-Unix...

[2] https://en.wikipedia.org/wiki/Single_UNIX_Specification#macO...