OpenRC
OpenRC is a dependency-based init system for Unix-like systems that maintains compatibility with the system-provided init system. OpenRC was originally developed for Gentoo, but is designed to be used on other operating systems.
OpenRC on FreeBSD
The OpenRC project officially supports and tests against FreeBSD upstream. A FreeBSD port for OpenRC has not yet been created.
GhostBSD used OpenRC
GhostBSD used OpenRC as its default init system before migrating back to FreeBSD rcd in July 2021 citing polling results and too much effort for one person to maintain. 1
FreeBSD Proof-of-Concept
JoeMaloney posted an OpenRC on FreeBSD RFC in March 2018.
In December 2018, MartinWilke announced a second FreeBSD OpenRC Proof-of-Concept after a 2018 FreeBSD Developer Summit Session, posting a FreeBSD review with code for running OpenRC on FreeBSD, OpenRC Demo Video and Tweet
The review was eventually abandoned in favour of "I will reopen it with a larger update.", but no further progress has been made to date.
More Information
GhostBSD OpenRC Wiki Page (wiki.ghostbsd.org)
Arch Linux Wiki: OpenRC (wiki.archlinux.org)
OpenRC: Interview with Joe Maloney (PDF, freebsdfoundation.org: FreeBSD Journal, August 2017)
Gentoo Wiki: Comparison of init systems (wiki.gentoo.org)
A Quick Compare of FreeBSD & GhostBSD Service Management (youtube.com by RoboNuggie 2)