WebPIE (Web-scale Parallel Inference Engine) is a MapReduce distributed RDFS/OWL inference engine written using the Hadoop framework. This engine applies the RDFS and OWL ter Horst rules and it materializes all the derived statements. WebPIE encodes Semantic Web reasoning as a set of Map and Reduce operations, tapping on the power of the MapReduce programming model for performance, fault-tolerance
