OBDA Plug-in for Protégé 3.3.1 (link)
The OBDA Plugin for Protege is an add-on for the Protege ontology editor aimed at transforming Protege into a fully fledged OBDA component editor. That is, it provides data source and mapping editors, as well as querying facilities that, in sum, allow you to design and test every aspect of an OBDA system. At the moment it supports relational data sources (RDBMS) and GLAV like mappings. More over, it provides additional querying facilities that allow the user to pose data centric queries to the reasoner.The OBDA plugin is also able to interact (synchronize/query) with any reasoner implementing the DIG 1.1 Interface plus the OBDA extension to DIG 1.1. Additionally, the plugin allows users to pose Union of Conjunctive Queries (UCQ’s) over the ontology; in order to answer these queries the reasoner can interface with any reasoner implementing the DIG 1.2 Conjunctive Query extensions defined by Racer Systems (link).
Update (02/Nov/09): Development for the Protege 3.3 version has stopped. All development is now focused on the Protege 4 version of the plugin, compatible with OWLAPI reasoners. This software is now under closed beta phase. If you would like to participate in the testing, please contact the authors. The expected release date for the Protege 4 and OWLAPI compatible versions of the OBDA Plugin is the first half of 2010. After this release, work will be put in compatibility with Protege 3.4.