at&t did at one time try to paint BSD as illegal. They also sued which Microsoft has not done yet.
That was a funny one. In the end AT&T was suing the BSD folks for using the technology the BSD folks developed and that AT&T was using without proper acknowledgement. I can only imagine what happened at the board meeting when this was disclosed.
But I get your point. Since then, AT&T got a lot more civilized.
Microsoft never was.
> GNU is pretty much a greatly enhanced superset of AT&T UNIX.
I know many people that would question your claim that GNU 'enhanced' the work of Bell Labs, more like the opposite, but then they were certainly not alone in that.
Mono implements a _subset_ of a proprietary offering that is Free (as in speech and beer). GNU is pretty much a greatly enhanced superset of AT&T UNIX.