I've put online at https://dspinellis.github.io/unix-history-man/ nine timelines detailing the evolution of 15,596 unique documented facilities (commands, system calls, library functions, device drivers, etc.) across 93 major Unix releases tracked by the Unix history repository. For each facility you get a timeline starting from the release it first appeared. Clicking on the timeline opens up the manual page for the corresponding release. (Sadly, the formatting is often messed up, because more work is needed on the JavaScript troff renderer I'm using.) The associated scripts and the raw data are all available on GitHub. Diomidis