FreeBSD's init (rc.d) system. See also: rcorder(8)

Yep, aka rcNG: https://www.usenix.org/legacy/events/usenix01/freenix01/full...

Yes. 1.5, if my mind serves correctly. Later on, LSB tried to do something similar for sysvinit using initscript headers that were interpreted by an external insserv program, but these proved to be far more fragile compared to rcorder(8).