groovy history

From Groovy creator (wikipedia): "I can honestly say if someone had shown me the Programming in Scala book by Martin Odersky... back in 2003 I'd probably have never created Groovy."

- quite funny, but still my choice is groovy, mainly due to its full interoperability with plain java )

Coolest RIA: smartgwt or not?

Considering GUI an effective RIA java app based on google app engine or other free java cloud hosting:

1. gwt gui library is very poor, even standart elements like datagrid - you'll have to expand to get simple things working (e.g. try to put image in a cell).
2. extgwt (gwtext) has one of the richest set of elements, but limitations with a license: you'll have to opensource your application if you use extgwt or pay.
3. vaadin - modern framework, but all things are handled on server-side, e.g. even onClick() handler. Extensive amount round-trips (commented details here).
4. jQuery/jQueryUI and other pure js frameworks - will force you programming with html/javascript/css besides java/groovy or what you are using on server-side. Do you know an cool IDE for all of that? )
5. ....
6. SmartGWT - analog extgwt with similar richest set of widgets and components with plain lgpl license (they sell only server-side java implementation)

Seems SmartGWT now is an optimal solution for gwt-based RIA where developer can concentrate on pure business logic w/o writing own datagrids, pagination and tuning html/css for different browsers.