Product review: Inside open source AJAX toolkits
Google Web Toolkit 1.4
License: Apache 2.0
Support: You can always type “gwt support” into google.com
Nutshell: A great tool for ex-Java Swing programmers and others who dig typed content
GWT's structure is more stable and produces a GUI that feels a bit more like a classic client application, circa 2000. This is why some GWT users are merging it with some of the other toolkits, producing hybrids like GWT-Ext, a fascinating mash-up that highlights some of the advantages of working with open source software.
The best matches for the GWT will continue to be former Java programmers, particularly those who know the Swing framework well. Most of the abstractions are close to direct analogs, something that's not surprising, given that some of the initial GWT developers were Swing refugees. This is attracting some of the sophisticated ideas from the Java world. Eclipse is easy for GWT users to adopt, and a new visual layout tool from Instantiations, GWT Designer, will warm the hearts of those who use the Matisse tool to build Swing applications in NetBeans. Shoot, some GWT developers are talking about writing their unit tests in Groovy!