UNIX
From Hackepedia
The word "Unix" refers to a fammily of operating systems descended from UNICS, way back in 1969. The [family tree] is quite interesting.
The name "UNIX®" (in caps) is a trademark held by [The Open Group], and covers a wide range of specific implementations conforming to the [Single UNIX Specification] (currently at version 3).
A few of the more common Unix based operating systems UBO:
