In a relatively short period of time the World Wide Web has
become a prominent vehicle for disseminating information. The
reason for its popularity is not so much its functionality per
se, but rather the convenience with which it provides access to a
variety of information sources. In fact, the functionality of
the Web, especially with respect to multimedia, is rather
disappointing with regard to the research in this area
Clearly there is a need to enhance the Web with dynamic
capabilities (for example to display multimedia and to allow for
interaction with the user) and with facilities for structuring
information, as advocated by the SGML standard
Another point of concern in the Web community is that with the increasing number of document formats, traditional monolithic browsers (such as Netscape) become too large and too inflexible to adapt to the needs of an individual user. In this respect our project takes a radically different approach, by allowing for a close integration between application-functionality and Web-functionality.
The DejaVu framework offers access to the Web as one of the
facilities in a collection of software components for developing
multimedia user interfaces and hypermedia applications. It
provides a vehicle for experimenting with true hypermedia
extensions to the Web. Our approach, which is essentially
object-oriented, allows for integrating the Web in applications
and vice versa, for composing a Web browser with support for
sound synthesis, digital video, 3D graphics and virtual reality
With the announcement of Java
We will first give an overview of the various components constituting the DejaVu framework and discuss briefly the architectural notions underlying our framework. Then, we will show how to employ these components to develop a Web browser with (client-side) support for animation, multimedia and virtual reality. Next, we will describe the concepts of encoding documents with SGML, and by giving some examples, we will illustrate our solution to defining the (browsing) semantics of arbitrary document types by means of script-based style sheets. And finally, we will discuss the requirements that must be met for developing a HyTime compliant browser for the Web.