The MAJ Courseware Sharing Exchange is a shared catalogue of Moodle courseware run by the Moodle Association of Japan. Teachers publish courses and activities to it from their own Moodle sites; other teachers find that material, look inside it before committing to it, try it out as a working Moodle in their browser, and import it into their own courses.
Everything in the catalogue carries an open licence, and no student data is ever uploaded — a shared course is a Moodle backup built with user data excluded.
