Topic: Java and XML
JrdfDB is an open source Java interface for rdfDB that allows querying the database using its query language and getting the results back as a row/column dataset in plain Java or as a result tree fragment of an XSLT eXtensible Style Language Transformation. (rdfDB is an open source database for Resource Description Framework (RDF) developed by R.V. Guha. XT is a Java-based XSLT implementation that uses the XP parser; http://www.xml.com/pub/r/XT.