Comment by FoeNyx

They are probably counting their monthly hits on http://www.learnpython.org/ and http://www.learn-c.org/ ( http://www.learnjavaonline.org/static/img/code.jpg style reflect the adaptation from their python website)

« By running real Java code directly from the web browser, students are able to try out Java without installing it. » their "directly from web browser" solution is using http://learnpythonjail.appspot.com/ so I wonder if it's using jython to interpret the java code.