systemd is a replacement for the init daemon for Linux (either System V or BSD-style). It is intended to provide a better framework for expressing services' dependencies, allow more work to be done concurrently at system startup, and to reduce shell overhead.
runit is a cross-platform Unix init scheme with service supervision, a replacement for sysvinit, and other init schemes. It runs on GNU/Linux, *BSD, MacOSX, Solaris, and can easily be adapted to other Unix operating systems.This app doesn't have any features at the moment.
OpenRC is a dependency-based init system that works with the system provided init program, normally /sbin/init. It is not a replacement for /sbin/init. OpenRC is 100% compatible with Gentoo init scripts, which means you can probably find one for the daemons you want to start in...
eudev is a fork of systemd with the aim of isolating udev from any particular flavor of system initialization. This is a project started by Gentoo developers to ensure udev remains system initialization and distribution neutral.This app doesn't have any features at the moment.
Using the tooling in this repo, I am able to boot from linux to sinit as PID1, and from there to Emacs acting as PID2 using --script mode, performing all typical rc.boot system initialization using Emacs lisp until we hit the getty.This app doesn't have any features at the moment.
procd is a process and system init service for OpenWRT. It's less resource intensive as it's intended for embedded devices, works with busybox and uClib, hotplug2, libubox and ubus. It watches configuration files to start or restart services and init scriptsThis app doesn't have any features at the moment.