Nextcloud, particularly with the Collabora Office integration for real-time collaborative document editing. It's got some rough edges but I'd say it suits the m

Nextcloud, particularly with the Collabora Office integration for real-time collaborative document editing. It's got some rough edges but I'd say it suits the majority of use cases now. I suggest spinning up a copy of the community edition in a VM to give it a spin, I was pleasantly surprised. There is a lot of money getting poured in right now as entities outside the US are exploring ways to ditch American software.