1. A data processing method executed by a processor comprising: subjecting one or more than one, in any combination, of a first entity comprising first meta-data, expressed using a semantic web language, defining at least one relationship between first software and at least one associated patch for the first software, a second entity comprising second meta-data, expressed using the semantic web language, defining at least one relationship between installed software and at least one installed patch for the installed software, and an ontology expressing concepts and relationships between software and at least one patch, to a query, expressed using the semantic web language, using a semantic web query language processing engine; and outputting data representing the result of said subjecting, said data relating to at least one of the first meta-data, the second meta-data and the ontology.