Links- Java RDF/OWL Tools
Of the 702 Semantic Web tools listed in Mike Bergman's masterlist, 332 are implmented in Java .... and Java now being a fully open source and open licence language ...
Stray link I'll find a home for: http://www.daml.org/tools/
SWCL - Semantic Web Client Library:
The Sematic Web Client Library represents the complete Semantic Web as a single RDF graph. The library enables applications to query this global graph using SPARQL- and find(SPO) queries. To answer queries, the library dynamically retrieves information from the Semantic Web by dereferencing HTTP URIs and by following rdfs:seeAlso links. The library is written in Java and is based on the Jena framework.
It is open source project and runs only in faily open source Java. The documentation is well written with lots of XML examples and could apply to any language.