OnlyOffice

OnlyOffice
Run your private office with Group-Office and OnlyOffice. Designed to make collaboration easy. A complete productivity suite to run your entire business with. Edit Text Documents, Spreadsheets and Presentations online in your browser.
You’ll need a working OnlyOffice installation first following their guides at https://www.onlyoffice.com.
When you have that setup and running. You need to install the module in Group-Office at System Settings -> Modules.

OnlyOffice Module installation
Check the box and add the appropriate permissions in the dialog that pops up.
Now reload Group-Office and go to System Settings -> OnlyOffice:

OnlyOffice System settings
Configure at least the URL to your OnlyOffice server.
Now you can open a document in the files module with OnlyOffice by right clicking on a file and choose ‘Open with…’.
Note
If you get a 404 error when editing because /onlyoffice is not found then you probably are missing the alias in your webserver configuration. The Group-Office Debian and Docker packages automatically create this but with the tarball package you have to do this manually. Example configuration can be found here.