There is. Atlassian’s Conflunce can be self-hosted on your own VPS. It is more of a Wiki-like knowledge sharing tool, but it also has collaborative editing mode

There is. Atlassian’s Conflunce can be self-hosted on your own VPS. It is more of a Wiki-like knowledge sharing tool, but it also has collaborative editing modes. It’s definitely no Google Office Suite since there is no support for sheets, but you can share and display them there and auto-upload office-files from the desktop to Confluence. It’s not perfect but it is an alternative.