MyMediaLite is a lightweight, multi-purpose library of recommender system algorithms. It addresses the two most common scenarios in collaborative filtering: rating prediction (e.g. on a scale of 1 to 5 stars), and item prediction from positive-only feedback (e.g. from clicks, likes, or purchase actions). MyMediaLite is free software (open source software), it can be used and distributed under the terms of the GNU General Public License (GPL).