5 JavaScript Frameworks

I stumbled upon this article today, while researching techniques for capturing the back button in JavaScript. This article highlights the features of 5 top-tier JavaScript frameworks:

1. YUI
2. Prototype
3. Rico
4. Qooxdoo
5. Dojo

Justin, says Top 5, but doesnt say what criteria he measured them by. Ignoring his ranking, these are 5 powerful Frameworks (although Rico is really an extension of the Prototype Framework). And I had not taken a look at Qooxdoo before:

Top 5 javascript frameworks