MusicBrainz Rating System
Rating is a new feature which has been introduced with the Server release of November 23th, 2008.
It allows users to rate MusicBrainz entities (artists, labels, releases and tracks).
Each user rating is a number between 1 and 5. Then the system aggregate users ratings to compute the average community rating.
By default community rating is shown. As soon as user rates an entity, he/she will only see its own rating.
Ratings display can be disabled in User Preferences for those you don't care about ratings.
Either by the new /rating resource for submitting/retriving one specific rating:
wget --user=<editor name> --password=<password> --post-data=id=8f6bd1e4-fbe1-4f50-aa9b-94c450ec0f11\&entity=artist\&rating=3 http://test.musicbrainz.org/ws/1/rating
or by using the new inc parameters
ratings, user-ratings with the artist, label, release or tracks resources as described in XMLWebService.