That was when AT&T first entered into anti-trust restrictions as a result of its anticomptitive practices in the long-distance telephone market, resulting among other things a 1958 DoJ consent decree preventing the company from marketing computer systems, which meant that in 1969, when Ritchie and Thompson wrote UNIX while at AT&T the company couldn't sell the software, and gave it away (with love, from Ken), resulting in most effective development moving outside the company by the mid/late 1970s (notably to UC Berkeley and MIT), a fact ultimately recognized by AT&T when it sold UNIX to Novell, who transferred the official UNIX trade mark to The Open Group in 1994.