TwistedWave - TwistedWave is one of the unique audio editors that allow you to edit your music file online without any installation.
WaveShop - Open source audio editor
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
WaveMax Sound Editor - WaveMax Sound Editor is an ideal solution for audio editing and mastering.
SunVox - SunVox is a small, fast and powerful modular synthesizer with pattern based sequencer (tracker).
SoundEngine - Freeware audio editor/recorder