Broad collection of widgets
Package system speeds loading
Spotty documentation
Google Web Toolkit
Fascinating/Simple Javascript to Java translation
Broad collection of widgets
Complicated to integrate with other Javascript apps
Microsoft Atlas
Deep Integration with .NET
Excellent documentation
Too integrated with Microsoft development tools
Open Rico and Prototype
Clean code
Sophisticated widgets
No package management
Yahoo AJAX Library
Good documentation
Easy interface for beginning programmers and HTML designers
Lack of larger widgets such as live table
Zimbra Kabuki AJAX Toolkit
Efficient widgets
Source available to large application using it
No package management
In closing Peter states that he expects to see more of a difference to evolve between the toolkits sponsored by one specific corporation and the toolkits sponsored by a collection of contributors. His final recommendation is to mix and match the best elements of the various toolkits instead of expecting one to solve all your needs.