JAXX is an open-source XML User Interface framework for Java. JAXX enables you to write simple XML files describing components and their interactions, and then compile those XML files into ordinary Java classes. User interface components can be developed much faster and more easily in JAXX than in ordinary Java code.

Key JAXX features not generally found in the competition:

JAXX is compiled, not interpreted. This means that JAXX programs run faster, require only a tiny runtime .jar file, and do not require a Java bootstrap program to launch them.
Java-based scripting and event handling means that Java code can be used almost anywhere in a JAXX file. JAXX scripts are compiled and run as fast as any other Java code.
JAXX files compile into ordinary Java classes, which means they are used exactly like any other Java class would be. JAXX classes can contain additional constructors, fields, methods, and anything else an ordinary Java class can.
JAXX tags allow you to create and interact with any class (both visual and non-visual), not just a small set of predefined components. You do not have to do anything special to import your own classes - just reference them by name.
Data binding allows you to set properties using Java expressions, and have the properties update in real time as the value of the expressions change.
Powerful CSS stylesheet support enables the skinning of entire programs using straightforward stylesheet files.

Integration between JAXX and Java is natural and seamless, as the classes compiled from .jaxx files are no different than the classes compiled from .java files. Because of this easy integration, JAXX can be used to write anything from a single dialog box to an entire application.