RacerManager is an open-source semantic web infrastructure that serves as a scalable front-end for applications to efficiently query OWL ontologies. It implements the candidate standard OWL querying language OWL-QL. OWL Query Language (OWL-QL) is a candidate standard language and protocol for query answering dialogues among Semantic Web computational agents using knowledge represented in the W3Cs Ontology Web Language (OWL). OWL-QL is a formal language and precisely specifies the semantic relationships among a query, a query answer, and the knowledge base(s) used to produce the answer.
RacerManager makes use of the OWL reasoning capabilities of the DL Reasoner RACER. RACER or RacerPro as it now called is an OWL reasoner and inference server for the Semantic Web.