[ex3ndr]

GWT allowed to run it without applets, also much more efficient than any current stack (since they dont support closure compiler)

[switchbak]

I spent years working with GWT, it's not nearly as simple as you describe. It's not running "Java" in the browser, it's compiling down (a subset of) Java to Javascript.

That said, GWT was ahead of its time in a lot of ways, but it had warts galore.