Addressbook is a project mainly written in GROOVY and JAVASCRIPT, it's free.
Grails/Vaadin integration demonstration with Spring Security based on addressbook application
This is the addressbook application described in Vaadin's documentation (http://vaadin.com/tutorial/-/page/preface.html) but modified to use Grails as a backend for storing persons.
This project uses the latest Grails-Vaadin plugin (plugin version 1.3 with Vaadin 6.5.1 inside).
It also serves as a demonstration of integration with Spring Security Core plugin.