I've re-visited GWT for a bit and it was as clunky and slow as always and it seems like it's hardly maintained and used by a very small number of people. That's not really correct. GWT 2.8 supports Java8 syntax that means you can leverage lambdas which make async code even more concise than the ES6 version. Furthermore SuperDevMode is really very fast. It's also not true that it is only used by few people and not maintained (check the github logs: https://github.com/gwtproject/gwt/commits/master , most commits are from Google Members but also contribution from the community). Also GWT is used for Google Inbox, Google Spreadsheet and used to write business code once in java and use it in iOS, Android and the Web. GWT 2.8 supports a brand new JsInterop (zero cost abstraction) that currently even easier to use than the Dart's JsInterop. Google is also working on GWT 3.0 which will be a pure Java to ES6 transpiler and reduce the compiler complexity a lot. There is also work done on leveraging Typescripts type definitions for various JS libraries to automatically create JsInterop Java interfaces to be used from GWT.