I'm just making this topic for the ones who are interested in questions with multi-language support.
Current we use C/C++, Java and Python for our programming problems. The coderunner multilanguage prototype was too simple. That's why I wrote our own multi-language template that has more features including cpu and memory limits, exam mode that hides testdata, testdata from a zip file, customization of grading function, adding hints.
Please share if your have any ideas / features / how to do it efficiently in this post. I'm especially curious about limiting memory / cpu time and showing time limit, memory limit errors.