I agree with @timeu that GWT's SuperDevMode is really very fast. Please compile and deploy demo Angular2 project in Java8 (GWT) from here: http://lteconsulting.fr/angular2boot/ . SuperDevMode is something what Dart doesn't have. At least recently. And all the conclusions come from the interview with Joshy Joseph (the primary technical lead for AdWords UI). Here is my Dart vs GWT comparison and for me Dart is still not matured enough. http://deploythoughts.blogspot.com/2016/04/the-new-adwords-ui-uses-dart-what-does.html It's like reinvent the wheel. Now they want to improve Dart and add things as following: Dart Strong Mode when GWT has stronger type checking out of the box, fast edit refresh when GWT has great SuperDevMode, and also would like to have better js interop what GWT has. Some of the things mentioned above could have been added recently, so this is the status from April. So I would rather think that Dart is slow and my choice if about Angular2 would be TypeScript, not Dart. But I can choose also Java. So I don't agree with your conclusions regarding GWT. It works well out of the box. Important thing is to use the latest version 2.8. Btw. today has been released 2.8RC1 and the final release is planned within 2 weeks. It's actively developed and new features are on the way. GWT 3 (J2CL) is now closer I agree with @timeu and I'm not going to repeat his words. If about Kotlin, yes it's interesting. But when I considered KotlinJS, the problem was with libs, frameworks and tooling. Another option would be ScalaJS where you can find more ready to use libs. Maybe we need more time for Kotlin. If about GWT the landscape is really huge and Java 8 is powerful enough. What more we have Javaslang and you can find support for GWT which is being developed: https://github.com/javaslang/javaslang/tree/master/javaslang-gwt . So complaining on GWT is rather about the past. There were the bad old days, but now it's being actively developed.