This paper introduces XHMBS (the eXtended Hyperdocument Model Based on Statecharts) to support the formal specification of general hypermedia applications. XHMBS uses a novel formalism called hypercharts as its underlying model for specifying the navigational structure, browsing semantics and synchronization requirements of a hyperdocument. Hypercharts are statecharts extended with additional mechanisms for describing the time sequencing and information synchronization requirements typical of multimedia. The extensions incorporated into hypercharts are based on the major characteristics of some Petri net based multimedia models, and make it an alternative to such models for multimedia and hypermedia specification. XHMBS provides facilities for defining the structure of a hypermedia application in terms of nodes and links and also for describing the temporal behavior of dynamic data streams contained in nodes. The model incorporates presentation and communication channels for describing...