[jmclnx]

That is because of the "lawsuite", unless you are referring to the 80s.

Back then, Companies and Colleges were the ones who got UNIX. Companies went with AT&T, and IIRC Colleges when with BSD. So AT&T won out due to better financial backing and maybe a possible threat of AT&T going after BSD.

[cpach]

Well, Linux is 30 now. The lawsuite was settled quite long ago, wasn’t it?

[jmclnx]

You did not specify a timeline. The book was written in 1984, BSD existed then and the only other UNIX was AT&T. Linux was not even a dream in 1984.