It is hard to tell from their web-site, at least if you don’t speak German and rely on the English text, that Knopper, founder or Knoppix, has made an effort from some time to provide freedom in init systems, After getting sysvinit to work (once again on a debian based distribution) this latest version 8.6 not only does it ship without systemd and associates, it contains a conflict pkg that prevents systemd from reinstalling. The package is called “no-systemd”. We welcome Knoppix to the wide non-systemd community and we wish it endless popularity.
AntiX has a package called systemd-must-die which is very similar 🙂
Since it is all debian based you can seek and install both and compare.