Just a quick note about a new version of JRDF. It's been a short time between releases but it still contains one significant advance over the previous one and that's persistent graphs. It's still in the early stages but it's basic enough for simple use cases. It also contains text serialization (based on NTriples) that is useful for moving RDF molcules around nodes in a cluster (for example). A lot of this code is fairly much "spike" code and I expect that another release will be released after we exercise these new features more (and write some tests/rewrite the code).
Update: 0.5.5.2 is now available fixing many bugs and introducing FILTER support.