CryptPad is a lot like Google Docs.

But if you just want collaborative text efiting, then EtherPad has been around since forever. There’s also a hosted instance available at framapad.org .

Cryptpad is really good for ad hoc collaborative text editing, with a couple bonuses:

  • the server cannot see what you and your friends are writing
  • you don’t need an account to participate in creating or editing a document