The vision of re-usuable, consistent, and flexible user interface components was presented early in the development of Sakai. A large effort resulted in a set of XML tags that extended JSF layouts. The idea was that if everyone used these tags, the user interface would be rendered in a consistent manner for all. While the idea was sound, several problems were encountered along the way:
JSF is not that easy to use and has some serious representation problems.
Creating JSF compoments that implement the tags is not easy and requires special knowledge.
People started using other presentation technologies like JSP, Struts, and even Servlets, none of which leveraged the idea of reusuable UI components.
RSF has a chance to breath new life into the idea of reusable components without the challenges presented by JSF.
This page contains information on the usage of Sakai Widgets in RSF.