Apache Pivot is an open-source platform for building rich internet applications in Java. It combines the enhanced productivity and usability features of a modern RIA toolkit with the robustness of the Java platform. Pivot applications are written using a combination of Java and XML and can be run either as an applet or as a standalone, optionally offline, desktop application.
Like other modern development platforms, Pivot provides a comprehensive set of foundation classes that together comprise a "framework". These classes form the building blocks upon which more complex and sophisticated applications can be built.
see here the apache pivot's project page