The World Wide Web (WWW) is curently one of the most important electronic information sources. However, its query interfaces and the provided reasoning services are rather limited. Ontobroker consists of a number of languages and tools that enhance query access and inference service in the WWW. It provides languages to annotate web documents with ontological information, to represent ontologies, and to formulate queries. The tool set of Ontobroker allows us to access information and knowledge from the web and to infer new knowledge with an inference engine based on techniques from logic programming.