JSA is a simple JavaScript application design pattern. The plugin supplies classes $.jsa.BaseAbstract and $.jsa.WidgetAbstract. With the first one you can create a hierarchy of application components which inherit properties of their parents in the way of class-oriented languages. Using the second you can make a YUI-styled widget out of your component. Thus your presentation components will match the same pattern, having renderUI section for transformation calls and syncUI to subscribe events.

Please find details int the article http://dsheiko.com/weblog/js-application-design