The TeaVM project is somehow related to GWT. But unlike GWT, it does not require you to provide the TeaVM compiler with the Java source code. Instead, TeaVM does some sort of decompilation of bytecode into the JavaScript source code, which gives TeaVM some advantages over GWT. TeaVM has a smart dependency checker that considerably reduces the amount of bytecode to decompile. Also, before building JavaScript, TeaVM does aggressive optimizations of the provided bytecode.
