The Google Web Toolkit Team just announced to open source their Eclipse Plugins ‘Google Plugin for Eclipse (GPE)’ and ‘GWT Designer’.
The Google Plugin for Eclipse provides tools for Google Web Toolkit and the Google App Engine.
GWT Designer is a GUI designer for GWT applications based on WindowBuilder. GWT Designer and WindowBuilder were originally developed as commercial products at Instantiations, Inc. that was bought by Google last year. Short after that, Google released the products for free use. In December 2010 Window Builder started as Open Source at the Eclipse Foundation.