ZK is an open-source web development framework that enables web applications to have the rich user experiences and low development costs that desktop applications have had for years. ZK includes an Ajax-based event-driven engine, rich sets of XML User Interface Language (XUL) and XHTML components, and a markup language.
![ZK Developer\'s Guide\](http://www.knigka.info/uploads/posts/dd091917ab9b7ef4ac610d5625185987.jpeg "ZK Developer\'s Guide\")
