The question was just asked in [18-24.3] Monitoring COVID19 effects if there are good tools for realtime collaboration on datasets, so I’d like to update this thread with a couple of suggestions of open alternatives to Google, Microsoft, Zoho, ONLYOFFICE, or other commercial web-based office programs, as well as a couple of up and comers:
Ethercalc is still actively developed and as far as I know is the easiest to use open source one-click online spreadsheet.
OpenRefine is going strong, had a new release at the beginning of the year with some neat features like Wikidata support. We have our own community-run instance, just ask for the password if you need it.
Nextcloud is the web-based version of LibreOffice, and there are plenty of good providers out there, including a few here in Switzerland, which won’t charge you an arm and a leg.
AirTable is a next generation product with a lot of integration and smart features. Groovy.
Notion is a popular new collaboration tool with table editing features, see Reading List template for example.