The provision and processing of information in an eScience environment are essential tasks. For this purpose, most environments provide information services which aggregate data from different information sources and make it available to users and other services. In this paper we present CIS, an extensible information service with an underlying unified information model. Designed according to service-oriented architectural principles, CIS consumes data from sources like Ganglia, formats it according to the Common Information Model, and delivers it against XQuery requests. We realised the information service in a Web Services environment and integrated it into an implied volatility application within the NextGRID project and the UNICORE middleware.