@lj_writes with @cryptpad we're developing a subset of those features. It's collaborative and encrypted in the browser so you need the keys to read the documents, but you can share them in a URL. Our next release will feature direct sharing with friends.
Federation is a harder problem since it's real-time, but we'd like to do that eventually.
@ansuz @cryptpad That sounds freaking amazing! Even without federation it sounds like it could be a replacement for Google Drive, which is pretty much irreplaceable for many people and they are stuck with it even if they hate being on Google. *goes to follow project*