The configarion files that systemd uses combined ideas from various distributions and didn't just use the ones that Fedora used before for example.Depends how you count. 15 people have commit access (from a number of backgrounds: Debian folks, community folks, Arch Linux folks, Red Hat folks, even one Canonical guy!). 373 people have contributed patches so far. The biggest part of core development is done by 3 people or so, but there’s a group of 10 people who regularly contribute major new components too. We have at least 5 people now who get paid for upstream systemd work.