Pellet
TenForce is the European distributor of the Clark and Parsia product suite. Pellet is the leading OWL reasoner for Java, supporting OWL 2 and extraordinary in its traceability of inconsistencies.
References
EDF
EDF incorporates Pellet in its in-house technology to calculate a customer's ideal subscription fee based on his consumption of electricity
NASA
NASA uses an HR tool running on Pellet to locate the right person with the right skills to staff a project, in a practical visual query browser
Read this blog on how NASA uses Pellet