JPOX provides transparent persistence of Java objects. It fully complies with the JDO 1.0 and JDO 2.0 specifications. It supports persistence to all of the major RDBMS on the market today. It allows querying using either JDOQL, SQL, or JPQL. It comes with its own byte-code enhancer. Its 1.1.0 release is Sun's "Reference Implementation" for JDO 2.0. Its 1.2 release will implement the JPA 1.0 specification and support persistence to DB4O. It is highly extensible using OSGi technology.
A bug has been fixed for attaching a CompoundIdentity 1-N relation. A bug has been fixed in the deletion of an embedded Collection. Improvements were made to the available SQL types for a datastore. Handling was added for read-only datastores and the action to perform if an update was attempted. Support was added for collections of interfaces where there is more than 1 implementation and discriminators are used. This is likely to be the final release in the 1.1 series.
URL: Java Persistent Objects (JPOX)