Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Ytmp3.cc - By using our converter you can easily convert YouTube videos to mp3 (audio) or mp4 (video) files and download them for free - this service works for computers, tablets and mobile devices.
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
OnlineVideoConverter.com - OnlineVideoConverter.
JACK Audio Connection Kit - JACK Audio Connection Kit|Home
VidToMP3.com - VidToMP3.