Constructing XML-speaking wrappers for WEB applications: towards an interoperating WEB

We discuss an architecture for integrating WWW applications that offer information and services in the same domain. At the center of this architecture exists a mediator, whose responsibilities are to interact with the user and to effectively exchange information with the underlying applications in order to accomplish the user´s task. The integration and interoperation of the existing applications are based on the availability of a common domain model, explicitly represented in XML. More specifically we have developed a general method for constructing wrappers for Web-based applications, so that they exchange data with shared semantics such as defined in the XML domain model. At run-time, the user´s requests result in the mediator´s XML queries to the application wrappers, which, in turn, invoke appropriate methods on the wrapped applications and extract XML data from their responses to these queries