The official answer to that question is simple. UNIX® is any operating system descended from that original Bell Labs software developed by Thompson, Ritchie et al in 1969 and bearing a licence ...

In the late '80s, Sun Microsystems and AT&T began a joint effort to merge BSD with System V, AT&T's version of Unix that they had commercialized following the breakup of the Bell System.

I know this.”, the Unix operating system (trademarked as UNIX) originated at Bell Labs where it initially was only intended for internal use to make writing and running code for systems like the ...