Beets is a media library management system designed for obsessive-compulsive music geeks. It catalogs your collection, automatically improving its metadata as it goes using the MusicBrainz database. It also downloads cover art for albums it imports. Then it provides a bouquet of tools for manipulating and accessing your music. Beets also includes a music player that speaks the MPD protocol, so you can play music in your beets library using any MPD client.
PASAP runs in the background, checking whether a stream exists, and, if it does, plays it. It was originally written to play back audio provided by MPD in remotely networked locations, but it also allows consumer-grade HD decoders (WDTV) to automatically play back audio/video streams from an HTTP address.
MPDisco is a Node.js-based music server built to let teams and groups control a single music player together. Accessing an MPDisco server puts each user, after logging in, in a rotating DJ queue. Each user will be given one hour (by default) to control the playlist and music player.