Though you may not be in the market for the complete email and collaboration server replacement that is Zimbra (see my previous post), there are always goodies tucked away inside large open source applications like this one. One such goodie is the Zimbra AJAX Toolkit (AjaxTK).
It’s still early days for Zimbra and complete documentation is still forthcoming, but there is a whitepaper available that documents AjaxTK from a rather technical standpoint.
The library of components included in AjaxTK is called the DHTML Widget Toolkit (DWT), and includes all the basic GUI components you would expect if you were coming from a desktop application development background. The included components provide for proper event handling, drag-and-drop operations, tooltips, and more, and the framework is designed such that you can write your own custom components that inherit these facilities as well.
As far as the actual AJAX functionality of the framework, server communications are neatly abstracted in to a set of networking classes, as well as a complete SOAP Web services client library. Once again, details like XMLHttpRequest implementation differences across browsers are totally hidden, so you can focus on what you’re trying to accomplish.
Though AjaxTK is by no means the only AJAX toolkit in circulation, it definitely looks to pack a lot of punch–especially for experienced developers who have a background in desktop application development. And with an impressive real-world application (the Zimbra client interface) to drive its development in a practical direction, its future looks bright indeed.