Kotlin sort of feels like Groovy "done properly" (with no disrespect to the authors of Groovy). Groovy kind of evolved in an opportunistic, unplanned manner and ended up with millions of features, cool whiz bang aspects that look awesome that don't always turn out well when you use them on a large scale. Kotlin seems to capture the same ideas (highly pragmatic, maintain perfect bidirectional compatibility with Java), but done in a much more thoughtful manner. Fingers crossed it works out.