Video DownloadHelper - Browser extension to download videos from the Web
Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Mp3jam - Search for favorite music and download full albums with one click! Features
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
Sonerezh - A self-hosted, web-based application for stream your music, everywhere.
JACK Audio Connection Kit - JACK Audio Connection Kit|Home