Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Cymbal - Music discovery powered by friends
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
humit - A social networking app for music sharing and discovery.
JACK Audio Connection Kit - JACK Audio Connection Kit|Home
discoverlocal.fm - Find and listen to artists performing near you this week 🎶