ZK 6.0.1 brings with it a whole host of new features and new components such as fushionchart integration and the biglistbox which is designed to use as little server-side memory as possible minimizing updating area to its viewport at client-side, displaying trillions worth of data at an amazing speed. Along with this, 6.0.1 also comes with numerous databinding improvements including reference binding, converter for children binding, form bean validator and more.
Release note: http://www.zkoss.org/product/zk/releasenote/6.0.1
New Features: http://books.zkoss.org/wiki/Small_Talks/2012/May/New_Features_of_ZK_6.0.1
Download: http://www.zkoss.org/download/zk