> AT&T licensed it free of charge to academic and government users in the seventies — until everyone was locked in. More nuance: firstly, there is a story, whi

> AT&T licensed it free of charge to academic and government users in the seventies — until everyone was locked in. More nuance: firstly, there is a story, which may be urban legend, that Thompson and Ritchie secretly gave source code to user groups, by leaving tapes in a predetermined outdoors location to be picked up. That set aside, AT&T was operating under a some kind of consent decree from 1956 which prevented them from entering the computer business. Which means that Unix couldn't be sold as a product. This is why they distributed it for just cost. When they got out of that decree, that's when they started to view Unix as a business asset.