Abstract : Recent developments of document technologies have strongly impacted the evolution of Web clients over the last fifteen years, but all Web clients have not taken the same advantage of this advance. In particular, mainstream tools have put the emphasis on accessing existing documents to the detriment of a more cooperative usage of the Web. However, in the early days, Web users were able to go beyond browsing and to get more actively involved. This paper presents the main features needed to make Web clients more active and creative tools, by taking advantage of the latest advances of document technology. These features are implemented in Amaya, a user agent that supports several languages from the XML family and integrates seamlessly such complementary functionalities as browsing, editing, publishing, and annotating.