There's been at least ten or so sysvinit alternatives that have existed before systemd. Some newer ones have appeared since then, most promising of which is nos

There's been at least ten or so sysvinit alternatives that have existed before systemd. Some newer ones have appeared since then, most promising of which is nosh. That said, all of the sysvinit replacements back then (eINIT, initng, depinit, s6, perp, etc.) never made it and were all ignored during their time.