ZK, undoubtedly is the best and free Ajax Java Framework. ZK is Ajax Java framework without JavaScript. With direct RIA, 200+ Ajax components and markup languages, developing Ajax/RIA as simple as desktop apps and HTML/XUL pages. Support JSF/JSP/JavaEE/Hibernate/.., and Ajax script in Java/Ruby/Groovy/Python/..

K is an open source Web development framework that enables Web applications to have both rich user experiences and low development cost as you did for years in desktop applications. ZK includes an Ajax-based event-driven engine, rich sets of XUL and XHTML components, and a markup language.

The event-driven engine brings the intuitive desktop programming model to Web developers.
The XUL and XHTML components enrich Web applications by off-the-shelf building blocks.
The markup language, called ZUML, makes the design of rich user interfaces as simple as authoring HTML pages.

[ Download ZK ]


  1. @Iantsai – I hope so too … They have a beautiful infrastructure laid down, and hopefully big things come their way so that life of a developer becomes much easier than it was ever before !!

  2. ZK used to be GPL Duel license in 3.6.X, which means if you don’t want to use it under GPL, you had to pay anyway.

    But now the community part become LGPL, which means you don’t have to pay even in commercial usage, and the Enterprise features are very limited and still free to Open Source project.

    I think ZK becomes more “open” than ever before.

    I wish one day ZK team can find a good Business model to earn it’s living and open more part to community.

  3. The problem is that ZK is leaving the fully LGPL license and going on a mix. The pricing page (http://www.zkoss.org/price/pricing.dsp) is pretty sad… almost all the most important components are going $$$ expensive $$$ and the community edition seems to be very limited.

    In the forums someone has asked them some clarifications and this is the answer he posted:

    Hello …,

    Glad to hear from you and thank you for your interest in ZK.

    With regard to the price,
    You can take a look at our pricing table here: http://www.zkoss.org/price/pricing.dsp#license

    This table is applicable to ZK 3.6 and prior versions. With regards to ZK 5.0, the items included in each package will be finalized before the official release scheduled by the end of the year. It may slightly differ from the current table and includes more new features, but offered at the same price as ZK 3.6. …

    … any ideas of other framework to use?


  4. I cannot agree more. I have used ZK for more than one and half year. Meanwhile, I tried other frameworks, too, — my boss forced me:( But, no one is comparable to ZK; no matter simplicity, features and productivity.

  5. Yes, zk is the best in most ways

    To us (TejaSoft), we find zk allows us to put in our best possible Design in place to build scalable and robust web applications.

    Most we like is combination of the following technologies used to help in increased developer productivity

    1. Templating approach to use the variables of java class (Expression Language)
    2. Rich set of UI components
    3. Very Active forum
    4. No page flow xml

    Raja Nagendra Kumar


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