Semantic interoperability is the ability of computer systems to exchange data with unambiguous, shared meaning. Semantic interoperability is a requirement to enable machine computable logic, inferencing, knowledge discovery, and data federation between information systems. Since the introduction of the Semantic Web concept by Tim Berners-Lee in 1999, there has been growing interest and application of the W3C (World Wide Web Consortium) standards to provide web-scale semantic data exchange, federation, and inferencing capabilities.