A system for processing data comprising: a plurality of resource interfaces each of which is operable to access a corresponding underlying resource, and a processor unit for integrating data accessed from the underlying resources and controlling a user interface. The user interface is operable in use to permit a user to view all of the underlying resources currently accessible to the system and to select a plurality of these to form a subset comprising some, but not all, of the underlying resources from which to form an integrated view of the sub-set. The processor unit is operable to store the selection within a user selection store and to determine how to join the data from the selected underlying resources to generate an integrated view of the selected sub-set of underlying resources and to generate data for transmission to a device for displaying the generated view to the user.