On: Results of the Debian systemd survey

Actually it's Redhat that went their own lonely path after trying out upstart and switching away, if I remember correctly. (RHEL 6 had it, to be precise)

However, it's not a lonely path in this case, because they chose to govern it in a contributor-friendly manner: no contributor license agreements, commit privileges for non-RH developers (non-RH developers are the majority), cross-distribution collaboration, FOSDEM presence etc. In short: They managed to build a healthy community around the project.

You can see the differences in numbers: http://www.ohloh.net/p/systemd http://www.ohloh.net/p/upstart

I think those systemd stats are skewed by having udev history imported... earliest commit is 10 years ago, which is far older than systemd.