1. A computer program product in a non-transitory computer readable medium for use in a data processing system that comprises a processor coupled to a network interface, the computer program product holding computer program instructions that comprise a function block, the function block having audio/video (A/V) call functionality, the function block operative when executed by the processor to: receive from a superblock application a request for an audio/video (A/V) service; determine that the superblock application is authorized to access the A/V service functionality; determine that the AN service requires access to a resource that is external to the data processing system; establish the A/V service between the superblock application and the resource via the network interface, wherein establishing is not otherwise supported by the superblock application; provide video output for the A/V service to a video window within a display window associated with the superblock application, the video window displayable simultaneously with the display window of the superblock application; and provide audio for the A/V service.