A component-based adaptation system is provided in which the operation of an application or the data being used by the application is adapted according to an application-specific or a user-specific policy. Following a request for a document by an application, the requested document is retrieved and converted into an application-independent format. The data of the document is then supplied to the application according to a user-specific or application-specific policy. The application of the policy may result in a lower fidelity version or a subset of the data of the requested document being supplied to the application. The policy may also govern the updating of the data supplied to the application. The data supplied to the application may be updated following the occurrence of a tracked event in the application or according to a background policy governing the supply of updated data without reference to the user's operation of the application. All of the adaptations are implemented without modifying the source code of the application and without modifying the document as it is permanently stored on a data server.