One of the most challenging issues in managing the large and diverse data available on the World Wide Web is the design of interactive systems to organize and represent information, according to standard usability guidelines. In this paper we define a framework to collect and represent information from different web resources like search engines, real-time networks and multimedia distributed databases. A prototype system has been developed, following the Rich Internet Application paradigm, to allow end-users to visualize, browse and analyze documents and their relationships in a graph-based user interface. Different visual paradigms have been implemented and their effectiveness has been measured in usability tests with real users. Key words: Information Visualization, Graph Drawing, Usability, Multimedia Databases, Social networks, Rich Internet Applications