La Suite numérique is a open source WIP office suite developped by french and german governments to replace proprietary office suite. Theyre self-hosteable but i found the official install instructions unclear to follow, and they have only instructions to install one app at a time. So i’ve used helmfile and did a one-command install myself.
Have fun
Here’s an alternative: https://www.opendesk.eu/en No guarantees though. But it looks nice.
I’m not affiliated with opendesk in any of way