A movie recommendation system according to genre or user ratings using IBCF. Item-based collaborative filtering (IBCF) uses item-to-item similarity based on user ratings to find items that are similar to the items the active user likes. This form of recommendation is analogous to "people who rate item X highly, like you, also tend to rate item Y highly, and you haven't rated item Y yet, so you should try it".
recommenderlab: An R Framework for Developing and Testing Recommendation Algorithms