GWT-Ext 
Posted on February 20, 2008
Widget Library
GWT-Ext is a powerful widget library that provides rich widgets like Grid with sort, paging and filtering, Tree’s with Drag & Drop support, highly customizable ComboBoxes, Tab Panels, Menus & Toolbars, Dialogs, Forms and a lot more right out of the box with a powerful and easy to use API. It uses GWT and Ext.