systemd is described as 'Suite of basic building blocks for a Linux system. It provides a system and service manager that runs as PID 1 and starts the rest of the system' and is an app in the network & admin category. There are more than 10 alternatives to systemd for a variety of platforms, including Linux, BSD, FreeBSD, Mac and OpenWrt apps. The best systemd alternative is OpenRC, which is both free and Open Source. Other great apps like systemd are runit, Launchd, s6 and sysvinit.
hummingbird is an init system designed for speed. It does nothing more than start the system and stop the system by default. There are three main "runlevels", fs which is called directly after the pseudo filesystems necessary for the system to run have been mounted...
