Web-based collaboration for editing electronic documents

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, include sending a first rich internet application over a data network from a web server to a first client device and to a second client device. The web server is adapted to allow multiple client devices to collaboratively access one or more electronic documents formatted for any one of multiple different applications, including the first rich internet application. A first electronic document, which includes multiple document elements, is sent from the web server to the first client device and to the second client device. A document update received from the first client device includes identifications of one or more of the document elements and a requested action with respect to the one or more identified document elements. The received document update is verified to determine whether the requested action complies with the document schema and whether the first client device is authorized to initiate the requested action. One or more updated document elements for the first electronic document is generated based at least in part on the verified document update and automatically sent to the second client device over the data network.