The standards developed in the context of the Semantic Web provide means of adding semantics to the data available on the Web. XML is a first level of semantics which allows users to structure data with regard to their content rather than their presentation. However, more semantics can be added with the Resource Description Framework (RDF) (1999) or Topic Maps (1999) standards. RDF was developed by the World Wide Web Consortium (1999) whereas Topic Maps were defined by the International Organization for Standardization (1999). The Topic Map paradigm was recently adapted to the Web by the consortium TopicMaps.Org (2001). Both RDF and Topic Maps aim at representing knowledge about information resources by annotating them.