Java DB is now part of Sun's JDK
Pure fiction or reality? well, this is one of the two and yes it has become a reality! - It is a very exciting event indeed to have an Open Source Java Database System bundled into Sun's *latest* 1.6 JDK (Mustang build 88 to be more precised), and at no cost.
It is a fully transactional, Java technology-based relational database with support for open standards such as SQL, JDBC, Java EE, Java ME CDC