Openwhyd - Collect and Share the tracks you love.
Lidarr - Lidarr is a music collection manager for downloading and organizing music libraries.
Zoff - Collaborate on a live music and video playlist with your friends.
Headphones - Automatic music downloader for SABnzbd. Headphones is an automated music downloader for NZB and Torrent, written in Python. It supports SABnzbd, NZBget, Transmission, µTorrent, Deluge and Blackhole.
Music Smasher - Find any song. Music Smasher searches Spotify, Rdio, SoundCloud, Bandcamp, and YouTube.
Lacey - Free Music & Video Downloader