WaveShop - Open source audio editor
Super Sound - Super Sound is a resourceful audio and music editor.
TwistedWave - TwistedWave is one of the unique audio editors that allow you to edit your music file online without any installation.
MixPad - MixPad is free music Music Mixer and Recording software designed for easy audio production.
Radium - Radium is a music editor with a new type of interface.
Add Audio to Video - Add Audio to Video empowers you to add custom audio tracks to your video files.