Given that it is also a server side language this is not surprising or worrying. It's no different than node.js specific code that doesn't work in the client.

Given that it is also a server side language this is not surprising or worrying. It's no different than node.js specific code that doesn't work in the client. I think it's just inherent to heterogenous environments. If they can do better than gwt I think they'll be fine.