What is your preferred scripting language in java world (scripting language on JVM) and way? When do you prefer your scripting language over java (in what situations for example for prototyping)? Do you use it for large projects or for personal projects only?
My favorite is Jython, and I use it by embedding a Jython interpreter in my Java application. It is being used in commercial projects, and it allows to easily customize the application according to the customers' needs without having to compile anything. Just send them the script, and that's it. Some customers might even customize their application themselves.