A release of OpenJPA includes the spec-jar, the kernel, and the user interface. The release is distributed as source code and as jar files that can be accessed via maven repository search.

• The spec-jar project contains the JSR-220 specification jars. This is the only artifact needed to build an application program that uses JPA.
• The kernel contains the broker, responsible for object-relational mapping, including utility and metadata model classes.

All are available for download as source and binary.

If downloading multiple source packages, extract them all into the same directory. This will preserve the source dependencies among the projects.