A blog post on the options for collaborative doc editing. i will open a ticket for preinstalling one from debian repos if you consider this usecase worthy enough.
Libre Software ones only? That will help choosing which one probably by a lot since not many left to choose from then?
Bonus: Anything server-less? Onions?
The only libre option with a Debian package that also happens to have been maintained for a long time and actively developed, is Gobby. https://gobby.github.io/
Gobby was specifically mentioned in Tails’ collaborative editing blueprint as workable behind an onion service: https://tails.boum.org/blueprint/server_edition/
NextCloud would have made a cool self-hosted cloud suite alternative but its not package for Debian. Etherpad and others use node js and we all know what the status of node js dependencies are…