Unix is basically a brand name.
BSD had to be completely re-written to remove all Unix code, so it could be published under a free license.
It isn’t Unix certified.
So it is Unix-derived, but not currently a Unix system (which is a completely meaningless term anyway).
Yup. It is all about paying the price, Microsoft could technically get Windows certified as UNIX. IBM did just that with its mainframe OS. Here’s a list of certified UNIX systems: https://www.opengroup.org/openbrand/register/
Unix is basically a brand name.
BSD had to be completely re-written to remove all Unix code, so it could be published under a free license.
It isn’t Unix certified.
So it is Unix-derived, but not currently a Unix system (which is a completely meaningless term anyway).
But OS X, macOS, and at least one Linux distro are/were UNIX certified.
Yup. It is all about paying the price, Microsoft could technically get Windows certified as UNIX. IBM did just that with its mainframe OS. Here’s a list of certified UNIX systems: https://www.opengroup.org/openbrand/register/