PolePosition - An open source Java database benchmark framework and results. [Open source, GPL] - http://polepos.sourceforge.net/
Java Database Tools, Products and Resources - Extensive list of utilities for OO, OR and relational database application development in Java. - http://www.javaskyline.com/database.html
The Apache DB Project - Project charged with the creation and maintenance of commercial-quality, open-source, database solutions. Mailing list signup, guidelines, repositories, and proposals. - http://db.apache.org/
CrossDB - An open source Java API for writing object oriented SQL statements that will run on any database. [Open source] - http://www.crossdb.com/