WaveShop - Open source audio editor
MixPad - MixPad is free music Music Mixer and Recording software designed for easy audio production.
TwistedWave - TwistedWave is one of the unique audio editors that allow you to edit your music file online without any installation.
Add Audio to Video - Add Audio to Video empowers you to add custom audio tracks to your video files.
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
Audio Video Editor and Mixer - Audio Video Editor and Mixer is a tool that helps you add changes to your video and audio files.