Castor provides a means to map data sources such as database tables and XML documents into a Java representation, providing a useful abstraction for developers. Castor consists of two main components: Castor XML and Castor JDO.

Castor XML is a schema object model that provides a representation of the W3C XML Schema Recommendation. It includes a source generator to create Java classes from a schema, and a marshalling framework that allows serialization of objects to and from XML instances. Castor JDO is an object-relational mapping that provides a similar framework for database persistence.

The change log for Castor 0.9.3.9 contains a detailed list of the bugs fixed in this release. Several new features have also been provided. In particular the schema object model has been extended to include a number of attributes and properties not previously supported.

The Castor team are now working on the 0.9.4 release. This will add an internal event API and give more control over source code generation.