From Site Search to the Semantic Web "We’ll further explore how Siderean’s faceted metadata resource discovery capabilities will bolster the viability of commerce that involves non-textual digital assets, including software components in the realm of Web Services. Next, we’ll examine how Siderean’s underlying technology, based as it is on RDF semantic encoding, makes Siderean Software's infrastructure a firm foundation for tackling problem number four, inference (or reasoning from data) in the decentralized world of the Web. Happily, cracking problem 4 upon an infrastructure of 1 through 3 is exactly what’s required to capitalize on the full potential of the Semantic Web." They are using Java 1.4.1 and any JDBC compliant database. They have some online demos.