Flexible Graph Layout for the Web

More powerful personal computers and higher network bandwidth has meant that graphics has become increasingly important on the web. Graph-based diagrams are one of the most important types of structured graphical information. Here we demonstrate how XML can be used as basis for contents-based delivery of graph-based diagrams. The main distinguishing feature of our approach is that it separates style and content of diagrams in the same way as (XML-based) markup languages for textual information do: The diagram itself is marked-up according to its logical structure and its visual appearance is defined via attached style-sheets. Such an approach poses interesting challenges for the browser component, because it requires automatic layout of complex diagrammatic information that takes stylistic constraints into account. We present a prototype system for our approach comprised of three main components: A contents-based markup language, GXML, for specifying graph-based diagrams, a style sheet language, GXSL, for such diagrams and a browser that can display styled graphs from this information.