Ask HN: What´s your favorite JVM Language?

Groovy, because it seems to have so much flexibility in what you can do with it. Its' the true "scala" to me in the sense that I can write single line bash scripts with it, but I can also write full fledged complex applications and high performance code that gets close enough to performance with Java and even C++ for most of my use cases. I can switch seamlessly between any level of static / dynamic typing to achieve whatever I want from among these different applications, and I can even do it after the fact.

Kotlin. Learning curve is gentle, reduced boilerplate, aggressive null handling, first class language support in IDEA and interoperability with Java codebase.

Groovy.

Because it's "java like" enough that all of my years of experience using Java still pay dividends, but yet it knocks off most of the warts Java has (writing getters and setters, for example), while adding cool stuff like dynamic typing, closures, currying, map literals, string interpolation, tons of handy convenience methods, etc.

Java

Kotlin!