[mathh]

+1 to Groovy.

Can be very simple and elegant, like a better Python, on the JVM.

But also very rigorous, as a Java superset, with powerful features like mixing dynamic and static compilation in the same class.

Or even deep, with run-time metaprogramming and compile-time AST manipulation capabilities (giving tools like Gradle, Spock...).

And you have of course multiline interpolated Strings. And so much.

[danudey]

I've been using Groovy extensively to script and automate inside of Jenkins, and hoo boy it's actually kinda nice.

My absolute favorite thing is being able to do something like:

    someIntegerCollection = someStringCollection*.toInteger()

I also find the use of closures for things like collection filtering to be quite nice:

    canadianUsers = someUserCollection.findAll { user ->
      user.countryCode = "CA"
    }

The equivalent in Python is a little more cumbersome and overly verbose:

    canadianUsers = [user for user in someUserCollection if user.countrycode = "CA"]

I'll still be writing things in Python whenever I can, but when I do write in Groovy there's a lot of nice stuff I get to have.

[Erlich_Bachman]

And if you need it, static typing is one annotation away... This is such an underestimated feature. While prototyping it might be easier to use dynamic typing, but once a project becomes complex and has more people working on it etc, - you might want to switch it to statically-typed. Groovy simplifies this immensely and minimizes the amount of code that needs to rewritten.