Seems like I just can't resist playing around with those acronyms ;)
Today's link takes you to an online test by the University of Düsseldorf which is designed to evaluate your English proficiency based on the official European frame of reference, in German "gemeinsamer Europäischer ReferenzRahmen", aka GERR. "My" 9th-graders might remember that this turned up in the fictitious CV in our textbook...
OK now, here goes:
Thanks again to Dr. Jörn Krieger for pointing me in the right direction ;)