Question: Is it possible to develop an application in groovy using GWT components?

Luis

Answer: 
If you want to use Groovy on the server-side and GWT for the UI, that is certainly possible. You can use Grails (a Groovy web framework on the server), and the [Grails GWT plugin](http://www.grails.org/plugin/gwt) to help you integrate GWT with this framework.
Right now you cant use Groovy on the client side. One big reason is that Groovy relies a lot on introspection, and this is not available on GWT.