Java™ DB is a relational database management system that is based on the Java programming language and SQL. Java DB is a commercial release of the Apache Software Foundation's (ASF) open source relational database project. The Apache project is called Derby.
The Java DB product includes Derby without any modification whatsoever to the underlying source code.
Technical support is available for purchase for the Java DB product through Sun.
Because Java DB and Derby have the same functionality, the Java DB documentation refers to the core functionality as Derby.
Java DB Version 10.3 is based on the Derby Version 10.3 release. References to "Derby" in the Java DB documentation refer to the Version 10.3 release of Apache Derby.