While I think JQuery is an impressive library, I think it is light to replace a full desktop UI programming model. As well Cappuccino favors the developer over

While I think JQuery is an impressive library, I think it is light to replace a full desktop UI programming model. As well Cappuccino favors the developer over the designer, in saying that their Atlas tool goes along way to remedy that. Currently, (my personal opinion) I think Dojo and to some extent YUI have the most robust libraries to replace the desktop UI development model.