Please excuse me if I’m terribly wrong, but from the information found on the project site it doesn’t seem like it’s primairy goal is supporting scripting, in applications such as games. It feels more like a way to “rip code out” in a way. However, it may work out good 
[quote]Analogously to the expression evaluator, a ScriptEvaluator API exists that compiles and processes a JavaTM “block”, i.e. the body of a method. If a return value other than “void” is defined, then the block must return a value of that type.
[/quote]
[quote]Janino is a super-small, super-fast Java™ compiler. Not only can it compile a set of source files to a set of class files like the JAVAC tool, but also can it compile a Java™ expression, block, class body or source file in memory, load the bytecode and execute it directly in the same JVM. Janino is not intended to be a development tool, but an embedded compiler for run-time compilation purposes, e.g. expression evaluators or “server pages” engines like JSP.
[/quote]
I don’t know. It just seems like a curious choice for scripting. 