Real-time document sharing and editing

Methods, systems and apparatus, including computer program products, for real-time document sharing and editing. In one aspect, a method includes comparing a first user's and a second user's changes to a document, the document being edited by the first user and the second user concurrently; and notifying the first user of a conflicting change and content of any conflicting change to the document made by the first user but not made to the document because of the conflicting change. In another aspect, a method includes recording a saved position of a cursor of a user editing a client-side copy of a document; receiving an update to the document and generating an updated client-side copy of the document; using the saved position to determine an updated position of the cursor; and displaying to the user the updated client-side copy of the document with the cursor displayed at the updated position.