[vbezhenar]

I tried Kotlin in one small project, which used Java API and I can recommend it. There are a lot of handy features there.

There were quite a bit of breaking changes, but, of course, it's expected from unreleased language. It wasn't hard to fix things.

For me Kotlin is in sweet spot between verbose Java and complex powerful Scala. From a practical point of view, I would prefer it to both. Any competent Java programmer will catch Kotlin fast enough, and it has almost anything I would want from a "improved Java" language.