One$DB

One$DB is an Open Source version of Daffodil DB, an commercial Java
Database. One$DB is a standards based (J2EE-certified, JDBC 3.0 and
SQL 99 compliant), platform independent, footprint size open source
database that can be embedded into any application and requires
zero or minimal administration. One$DB can be easily deployed and
embedded in a variety of Java-based applications. It has been made
available in both Embedded and Network editions.