Product review: Inside open source AJAX toolkits
License: Commercial or LGPL 3.0
Support: Ext offers its own consulting and training services
Nutshell: A commercially backed project with sophisticated tools and a professional bent
Ext is another framework that appeared out of nowhere and began to capture developers immediately with a very rich collection of widgets and a polished collection of documentation. The project is more a commercial venture that offers a practical open source license (LGPL) in parallel with strictly commercial licenses, training, and support.
The library is also built around the same super-DOM object mechanism that wraps the DOM element up so that the semantics are much simpler. Many of the details of iterating over elements and dealing with null objects are hidden away by a well-designed collection of methods. In just a short line of code, you can select all paragraphs and attach a method, clickedHere, that fires on a click:
The strongest parts may be the depth of the widget collection. The grid tool offers a deep collection of mechanisms for displaying, sorting, and filtering tabular data. There are also hybrid grid tables, live search boxes, toolbars, tabs, and trees. All are sophisticated and well-integrated.
There is an active user community, although it doesn't seem to have the same depth or fervor as other groups. This may be one of the costs of a strong, centralized commercial presence that has already handled most of the heavy lifting, saving some clever programmer the need to extend the toolkit. One of the nicer features is a collection of user-contributed themes that let you quickly change the look of the widget collection.
Ext is a fast-growing community offering sophisticated widgets and tools in an attractive professional package. It is a very effective mixture of commercial sophistication and open source freedom.