Cryptpad.fr

I appreciate everyone in this thread giving actually useful replies instead of pointing out that OP could have posted in a more suitable community.

@trippingonthewire
Nextcloud and Collabora in combination. If you dont want to host your own nextcloud, there are providers offering a hosted nextcloud with collabora. editing spreadsheets from a mobile device (tablet, smartphone) does not work very smoothly, the rest is great, also collaborative file editing.

Collabora.

If you like compatibility with MS Office, Onlyoffice.

I think Nextcloud has some collaborative office stuff

https://etherpad.org/

Etherpad is my personal recommendation.

@trippingonthewire There is also Hedgedoc hedgedoc.org/

My friends and I use Obsidian and Syncthing. It's a bit tricky if you try to edit simultaneously but it works if you edit at different times.

Edit: not foss

I think framasoft also has an option for a google docs alternative! They're the folks who made peertube

Infomaniak kdrive is open source*

• = it's using onlyoffice web version + their desktop clients and mobile clients, which is AGPL 3 but it's not really a community effort like LibreOffice, rather a commercial product

Hedgedoc / codimd. Collaborative markdown.

Etherpad works, but it's not markdown.

What kind of formatting do you need? Something no too complex that is markdown-based would be enough?

Try Typst! It's quite awesome! I wrote my thesis with it :)