Here is a selection of open source libraries we have been playing with recently. Someone out there may find these useful..
Digester is a great tool for mapping an incoming XML SAX stream into Java object/s, based on certain user defined rules. These rules allow one to instantiate and populate objects depending on the content of the SAX stream.
Xstream is library to serialize objects to XML and back again, so its useful for persisting objects for example.
Velocity is a Java-based template engine, allowing one to call Java methods from within XML templates. In some quarters its seen as an alternative to Java Server Pages (JSPs) or PHP.
Quartzscheduler an open source scheduling system written in java. Allowing for easy cross platform scheduling. No need to tie ones self down to Unix Cron or Windows scheduler.
Jarapac is a "transport-independent client- and server-side framework for DCE/RPC in Java" Its great for invoking MSRPC from non windows platforms. I have posted about earlier.
Koders is a source code search engine. Check out
Java commons IO for even more goodies.