Two different representations of content are maintained, at least one of which is a composite representation of the content. The composite representation is multiple different components, each component stored as a separate file and each component including some of the data of the content. The composite representation also includes a manifest that identifies the various components. Different devices can edit the content, and access to the content is coordinated via a synchronization system. The synchronization system manages generation of one or more representations of the content. The synchronization system also manages synchronization of the different representations of the content, allowing changes made on various different computing devices to be reflected in the different representations of the content, and managing situations in which different computing devices may attempt to change the content concurrently.