With ZK, you represent your application in feature-rich XUL and XHTML components and manipulate them upon events triggered by user's activity, similar to what is done in desktop applications. Unlike most of other AJAX frameworks, as far as ZK is concerned, AJAX is a behind-the-scene technology. The synchronization of component content and the pipelining of events are done automatically by the ZK engine.
Your users get the same engaging interactivity and responsiveness of the desktop application, while your development retains the simplicity of developing desktop applications.
In addition to a simple model and rich components ZK also supports a markup language called ZUML. ZUML, like XHTML, enables developers to design user interfaces without programming.

