Comment by DSpinellis
6 hours ago
I published an updated extension of this post's linked article in Empirical Software Engineering. You can read it without a paywall at https://rdcu.be/b7FzE. You may also be interested to see the actual GitHub repository at https://github.com/dspinellis/unix-history-repo.
Right. The title of this submission should have a "(2015)".