This is our fifth post in the Rebel Labs review of Java web frameworks, having already covered Vaadin, Grails, Spring MVC and Wicket. Today we look at GWT (Google Web Toolkit), which Google announced back in 2006 at JavaOne and has been worked on actively since then. In our Developer Productivity Report, GWT maintained a 14% market share, falling into 4th place behind Spring MVC, JSF and Struts. So let’s take a deeper look and see what it has to offer.