This page discusses technologies for implementing user interface
* The main point here was that in GWT (and SmartGWT) the size of the client-side grows when the application grows. In Vaadin client-side size is static and lean even for huge applications.
* Apache licence
* GWT based (client side widgets)
* Community (addons!)
* Matt Raible: Top 5 UI framework http://www.slideshare.net/mraible/comparing-jvm-web-frameworks-tssjs-2011 (Grails,Rails incl)
* Vaadin scalability study: http://vaadin.com/blog/-/blogs/vaadin-scalability-study-quicktickets