hsqldb.org
RDBMS with JDBC interface, client-server version, query tool, grid, tree, performance test class, servlet, and self-test program. Also supports pure in memory databases. [Open Source, BSD-like]
RDBMS with JDBC interface, client-server version, query tool, grid, tree, performance test class, servlet, and self-test program. Also supports pure in memory databases. [Open Source, BSD-like]