Keyword-based search engines, though hugely popular, show limitations when trying to answer very specific queries. The processing of search results is performed by users, rather than by software. Ontologies provide a means to create formal, machineprocessable descriptions of the knowledge in a certain domain [14], and, by using elements of these descriptions to annotate suitable information sources, they can be analysed and manipulated in an intelligent manner. The QuestSemantics platform provides automated ontology-based metadata creation and resource annotation, with subsequent ontology-based querying of the annotated resources. The platform has been deployed in two commercial scenarios, providing useful feedback on both the feasibility and effectiveness of applying Semantic Web technologies to specific business problems.