http://webtoolkit.eu is for me the future of web development: let the framework handle all the plumbing.
Mojito claims to blur the client/server boundary. With Wt, you don't see it anymore. If you're a web developer, really worth a try!
It is not similar to GWT: GWT is client side only, with Wt you develop one code-base all in one language (C++ or a JVM language) that handles transparently server side and client side operations, including communication between both sides.
