SweetRules is a uniquely powerful integrated set of tools for semantic web rules and ontologies, revolving around the RuleML (Rule Markup/Modeling Language) emerging standard for semantic web rules, and supporting also the closely related SWRL (Semantic Web Rule Language), along with the OWL standard for semantic web ontologies, which in turn use XML and, optionally, RDF. (SWRL rules are essentially an expressive subset of RuleML rules.)
SweetRules supports the powerful Situated Courteous Logic Programs extension of RuleML, including prioritized conflict handling and procedural attachments for actions and tests. SweetRules' capabilities include semantics-preserving translation and interoperability between a variety of rule and ontology languages (including XSB Prolog, Jess production rules, HP Jena-2, and IBM CommonRules), highly scaleable backward and forward inferencing, and merging of rulebases/ontologies. Procedural attachments can even be WSDL Web Services.
SweetRules' pluggability and composition capabilities enable new components to be added relatively quickly. Implemented in Java, SweetRules has a compact codebase (~40K lines of code total for several dozen tools).
The SweetRules project is an international, multi-institutional effort, originated and coordinated by the SweetRules group at MIT Sloan led by Benjamin Grosof, and its creation was funded largely by the DAML (DARPA Agent Markup Language) research program which co-pioneered the Semantic Web.
SWEET ("Semantic WEb Enabling Technology") is an overall set of tools that Benjamin Grosof's group (with collaborators) has been developing since 2001. Other components in it include the SweetDeal e-contracting system approach and prototype, and the SweetPH system for business process ontologies drawn from the Process Handbook.
Hundreds of users have already downloaded SweetRules, inspired in part by its well-received demonstrations in detailed presentations at the DAML Principal Investigators Meeting and the International Semantic Web Conference tutorial program.