WaveShop - Open source audio editor
SoundGrail - SoundGrail Music App designed for pianists, guitarists, and DJs.
TwistedWave - TwistedWave is one of the unique audio editors that allow you to edit your music file online without any installation.
Figure - Propellerhead creates world-class software products and services that inspire music makers and provide the foundation for a worldwide creative musical community.
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
keezy - A colorful soundboard. Play with music.