FOSS init "SysVinit" has been updated to version 3.10. This update was a small one that fixed one bug, improved documentation and improved compatibility with systemd's machinectl command. The code to SysVinit is licensed using GPLV2. You can find some distros shipping iso's with SysVinit as an option or the sole init such as Artix; PCLinuxOS; Deuvan; and more.
The source code can be found on Github:
https://github.com/slicer69/sysvinit
Release notes for this update can be found here: