Skipforward is a distributed recommendation system using a lightweight ontology approach for formalizing opinions about item features. Items can be things such as songs or board games; example item features are the genre of a song or the degree of chance in a board game. Every user of the system is free to add new items and statements about existing items to the system. Naturally, opinions may differ between users---the system even encourages people to express dissent by supporting negation for item features. Skipforward allows discussions for any item feature as well as displaying these discussions in a way similar to web forums.
There exist some demo installation with custom data and data from DBTropes