[dredmorbius]

I'll argue that the true innovation of Linux was in the licensing, with both the development and adoption model this implied. Early Unix was distributed without a license (for numerous reasons). It rapidly spread throughout research and academic circles, but was constrained once software licensing emerged in the 1980s, and finally killed in the BSD wars of the 1990s.

It's not that Linus stumbled on some secret of technology or was smarter than anyone else doing 'Nix development. It's that he got obstructions out of the way that kept those who could contribute meaningfully from being able to do so and allowed others to utilize the results.

The end result is the innovation and technical superiority (by and large) of Linux over alternatives.

On how Unix initially emerged: there was no copyright of software (this changed in 1976), and AT&T were prohibited under a 1954 anti-trust consent decree from participating in computer equipment and software. So when Ritchie and Thompson created Unix, the company could do little but use it internally, and had no reason to prevent its more widespread distribution. Unix exists specifically because AT&T was prevented from productizing it.