AudioCutter Cinema offers you a wide range of functions for creating, changing, converting and editing of common and of surround sounds.
blue is a program for use with Csound. It's interface is much like a digital multitrack, but differs in that there timelines within timelines (polyObjects). This allows for a compositional organization in time that seems to me to be very intuitive, informative, and flexible.
Eisenkraut is a soundfile editor implemented as a SuperCollider 3 frontend. It's cross platform and requires a java 1.4 VM. Separate packages for the independant libraries JCollider (java client for SuperCollider) and NetUtil (OSC for java) are provided.
Kangas Sound Editor
Kangas Sound Editor is a Kangaroo-themed program that allows the user to create music and sound effects. It uses a system of frequency ratios for pitch control, rather than conventional music notation and equal temperament. It allows instruments, both musical and percussion, to be created.
Kangas Sound Editor QI
Kangas Sound Editor QI lets you synthesize sound effects and music effectively from scratch.
Layer-based AudiO Editor: an audio sample editor suitable for manipulating sound