Since Gottlob's arrival in early 2006, we have built a leading group in databases. With Horrocks' arrival in 2007, it is developing into a world-leading group in information systems, concentrating on the twin themes of databases and knowledge representation. Other researchers recruited to this group include Benedikt, Cali, Kreutzer, Motik and Olteanu. Our database research addresses topics ranging from query languages and optimisation to web data extraction and the implementation of lightweight database applications for devices such as mobile phones. Horrocks and Motik's main interests are in knowledge representation and reasoning, in particular Description Logics and their application in ontology languages and engineering. Key achievements include Gottlob's highly cited work on the XPath Query Language, which also gave rise to a patent; his work on Information Extraction (best paper, PODS'02), the commercial version of which was a finalist in the 2003 World Technology Award competition; and his work on Hypertree Decompositions (best paper, PODS'07). Horrocks played a central role in the development of ontology languages such as OWL (now a W3C recommendation), and the description logic dialects, decision procedures, and optimised reasoning systems that made OWL possible. Benedikt's work on XML integrity-constraint management tools is now used in many safety-critical systems (e.g. by Alcatel-Lucent), and his work on social search algorithms is being prototyped at Yahoo. Motik won the 2007 ERCIM Cor Baayen award for his work on reasoning algorithms and systems for description logics.
