I remember that I self hosted an EtherPad instance https://github.com/ether/etherpad-lite https://github.com/ether/etherpad-lite There was something like that

I remember that I self hosted an EtherPad instance https://github.com/ether/etherpad-lite https://github.com/ether/etherpad-lite There was something like that for spreadsheets too but I can't remember what. The only collaborative projects I had to work on were with customers so we always used Google Docs, nothing self hosted.