Devuan GNU+Linux is a free software operating system for your
computer. Free software means you are free to use, copy
and distribute, study, change the software, and share your
modifications with the community.
software freedom, your way
apt install sysv-rc
admin : required
System-V-like runlevel change mechanism
This package provides support for the System-V like system
for booting, changing runlevels, and shutting down,
configured through symbolic links in /etc/rc?.d/.