Google Docs is a free and fairly user-friendly document creating, collaborative editing, and sharing silo from Google that sometimes fails inexplicably.
Perhaps the most important feature of Google Docs, collaborative editing, if often blocked, because of a "Sharing unavailable" error preventing you from sharing the document with others to edit together.
When you click the blue [Share] link/button in the top right corner, sometimes you'll see a spinning cursor for a bit and then this alert:
- Tantek Çelik: I have seen this error at least once a day when attempting to share a Google Doc with others. In comparison I have never had nor seen any similar problem with Etherpad.