A transcript from (the latest) Debian Handbook:

A.9. Devuan
Devuan is a relatively new fork of Debian: it started in 2014 as a reaction to the decision made
by Debian to switch to systemd as the default init system. A group of users attached to sysv
and opposing (real or perceived) drawbacks to systemd started Devuan with the objective of
maintaining a systemd-less system. As of March 2015, they haven’t published any real release:
it remains to be seen if the project will succeed and find its niche, or if the systemd opponents
will learn to accept it.