Sayonara - Linux audio player and music library manager
Knowthelist - Knowthelist - the awesome party music player Easy to use for all party guests
Mopidy - Mopidy is an extensible music server written in Python. Mopidy plays music from local disk, Spotify, SoundCloud, Google Play Music, and more. You edit the playlist from any phone, tablet, or computer using a range of MPD and web clients.
Song Director - Song Director is a program that plays and keeps track of all your music files.
Oceanaudio - Ocenaudio is a cross-platform, easy to use, fast and functional audio editor.
MixTape - Home of MixTape, an OSX application for creating beat matched mixes with simple export to the web or iTunes.