If you look around you should still be able to find Luke Mewburn's paper on #MewburnRC .
Similarly, what Linux people erroneously call "sysvinit" is actually van Smoorenburg init+rc created (by Miquel van Smoorenburg) for Minix in 1992.
It's not from #Unix System 5 at all, as that had obsoleted R3's init+rc system years before 1992 and gone on to the AIX SRC, and the SAF, SAC, ttymon, SMF, and stuff still in #Illumos today.
jdebp.info/FGA/unix-service-acβ¦
FGA: The Unix Service Access Facility
Frequently Given Answer explaining the Service Access Facility that Unices have.jdebp.info