MITx on edX: Free online courses from MIT: MITx provides free online courses developed and taught by college from the Massachusetts Institute of Technology. Whether you are ... atOptions = { 'key' : 'a8dfc29b76f8e0e43144f40c1f6e4e79', 'format' : 'iframe', 'height' : 90, 'width' : 728, 'params' : {} }; document.write('');