Here is an overview of the extensions of ZK. They are optional. If you are new to ZK and prefer have some knowledge of ZK first, you could skip this section and come back later after you understand more about ZK.
There are hundreds of projects which extend ZK's functionality by boosting programmer productivity, providing sample code and many others. For more projects, you could search ZK Project-Info, Google Code, Sourceforge.net, GitHub, ZK Forge etc.
IDE and Tools
ZK Studio is a visual integrated development environment for developing ZK applications with Eclipse IDE.
ZATS is a testing toll to automate ZK tests without the need of a browser or a server.
ZK CDT is a component development tool which provides wizards to simplify the creation of ZK components.
ZK Jet is a browser extension that works with Firefox and Google Chrome. This provides users with a ZK sandbox environment.
Use this plugin's embedded Jetty distribution to run web applications in Eclipse. This helps to speed up the ZK development by minimizing the deployment time. The project is maintained by Tony Wang, a member of the ZK Team.
Libraries and Integrations
ZK JSP Tags is a collection of JSP tags built upon ZK components, such as that developers could use ZK components and other JSP tags in the same JSP page.
ZKGrails is a ZK plugin for the next generation rapid Web development framework, Grails.
ZK addon for Spring ROO enables rapid development of ZK / Spring / JPA projects using Spring ROO.
ZEST is a lightweight MVC and REST framework which provides an additional page-level MVC pattern to isolate the request's URI, controller and view (such as ZUML document).
ZK CDI is integrated with ZK and JBoss Weld CDI RI.
ZK Seam is integrated with ZK and Seam.
ZK JSF Components are a collection of JSF Components built upon highly interactive ZK Ajax components.
Components and Themes
ZK Themes is a collection of various themes, including breeze, silvertail and sapphire.
Keikai is a ZK component delivering spreadsheet functionalities like Microsoft Excel to a web application.
ZK Pivottable is a ZK component for data summarization that sorts and sums up the original data layout.
ZK Calendar is a ZK component enabling rich and intuitive scheduling functionality to ZK applications.
ZUSS (ZK User-interface Style Sheet) is an extension to CSS. It is compatible with CSS, while allows the dynamic content, such as variables, mixins, nested rules, expressions, and Java methods with existing CSS syntax.
ZK Incubator Widgets hosts a collection of incubator widgets, tools and add-ons.