Yahoo AJAX Library

Yahoo's AJAX library is not only a solid collection of functions (http://developer.yahoo.com/yui/) but also a good illustration of how to publish open source software. The code for adding a core group of widgets to your Web application comes in a zip file, and Yahoo offers a wide variety of examples and design suggestions. Many of the routines come with six to 10 different examples, all with sample code and demonstration pages.

This approach is markedly different from the other packages because Yahoo is just as intent on pushing a clear design philosophy as it is on delivering a piece of code. This tactic is more important than it may seem because the general user still needs a great deal of education about how AJAX applications behave. The designers at Yahoo want to push a stable, consistent behavior for the AJAX widgets, and their very complete documentation encourages this.

The collection of features in the Yahoo library is solid but not as large as Dojo's. It has many of the standard tools, such as an animation library and a tree collection, but there are few of the larger, more substantial tools such as an editor or a live table.

Yahoo does add some nice touches. The animation library, for instance, also interacts with some standard tools, such as a text scroll device that allows you to automate the behavior of some part of the HTML -- say, a box filled with text. The Connection manager will automatically assemble all of the data from a form and put it into the right format for a GET or POST application.