Apache Isis™ software is a framework for rapidly developing domain-driven apps in Java. Write your business logic in entities, domain services and repositories, and the framework dynamically generates a representation of that domain model as a webapp or a RESTful API. For prototyping or production.
Isis graduated from the Apache incubator in October 2012; we released Isis Core 1.0.0 plus 4 supporting components in December 2012.
Our documentation page has plenty of useful content.