foobar2000 - An advanced freeware audio player for the Windows platform.
BeatSense - Discover great music hand-picked by real people, in a single click. FREE and in real-time!
üWave - üWave is a self-hosted collaborative listening platform.
noidd.com - Enable users to share music and videos LIVE with others people on customizable channels.
musiqpad - Musiqpad is a social-music software platform for users to host their own ‘pads’ (rooms).
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.