Employing smart browsers to support flexible information presentation in Petri net-based digital libraries

For effective real-life use, digital libraries must incorporate resource and system policies and adapt to user preferences and device characteristics. The caT (context-aware Trellis) hypertext model incorporates these policies and adaptation conditions within the Petri net specification of the digital library to support context-aware delivery of digital documents in a dynamically changing environment. This paper describes extensions to the caT architecture for supporting adaptation via smarter browsers and an external resource store to provide greater flexibility in information presentation. Browsers request resources that they can best display with their knowledge of intrinsic capabilities and constraints imposed on them by the devices that they run on. The data store returns the most appropriate version of a resource in response to browser requests, thus allowing maintainers of libraries to add, modify and remove resources without any changes to the structure, presentation or document pointers in the digital library.