Nice and clear explanation of what's going on under the hood. But it does simply underline my initial impression of Kotlin - that it's really just Java with less boilerplate, cleaner handling of nulls, and some modest improvements in semantics and lambda features. So we're talking about incremental improvements here, rather than the radical potential of a true functional language like Eta. For shops that want to stick to OO, I suspect that Kotlin has a bright future and that it will gradually displace vanilla Java. Particularly with the IntelliJ tooling, which is outstanding. For more adventurous developers looking for larger gains, it's exciting to see pure functional languages making their way onto the JVM at last.