EclipseLink is the open source Eclipse Persistence Services Project from the Eclipse Foundation. The product provides an extensible framework that allows Java developers to interact with various data services, including databases, XML, and Enterprise Information Systems (EIS). EclipseLink supports a number of persistence standards including the Java Persistence API (JPA), Java API for XML Binding (JAXB), Java Connector Architecture (JCA), and Service Data Objects (SDO).
EclipseLink is based on the TopLink product, which Oracle contributed the source code from to create the EclipseLink project. The original contribution was from TopLink's 11g code base, and the entire code-base/feature set was contributed, with only EJB 2 CMP and some minor Oracle AS specific integration removed. This differs from the TopLink Essentials Glassfish contribution, which did not include some key enterprise features. The package names were changed and some of the code was moved around.
The TopLink Mapping Workbench UI has also been contributed to the project.
EclipseLink is the intended path forward for persistence for Oracle and TopLink. It is intended that the next major release of Oracle TopLink will include EclipseLink as well as the next major release of Oracle AS.
EclipseLink supports usage in an OSGi environment.
EclipseLink was announced to be the JPA 2.0 reference implementation, and announced to be the JPA provider for Glassfish v3.