The description of an update package for updating a software application in an offline synchronization operation is presented. The update package includes update information for a plurality of updates. The update information includes a reference to the update payload and the relationships of the present update to other updates in the update package. A system for updating a software application on a client computer is also presented. An update agent includes a communication module and a media module. The communication module is configured to communicate with both an update source over a communication network, or the media module. The media module obtains update information from computer-readable media. The communication module communicates with the update source or the media module in the same manner.