Docs: a document inside every record — Saving and version history

A doc saves as you type. Each stretch of editing is kept as a version: when you have been idle for ten minutes, when you leave the page, a few minutes after a tab is closed, and every half hour of continuous writing. History lists every version. You can read one, compare it with the current doc (added words are marked, removed words struck through), restore it, or give it a name such as Sent to client. Restoring keeps the doc as it was first, and nothing in history is ever deleted.