OnlineSequencer.net - OnlineSequencer.net is an online music sequencer that allows users to create beats and music tracks.
Fission - Edit audio in minutes, not hours.
GoatTracker - This is a crossplatform C64 music editor.
Audio Cleaning Lab - Looking to clean up your song recordings? Download SOUND FORGE Audio Cleaning Lab, the professional solution for cleaning & restoration with advanced ProAudio technology.
Jummbox - A modified Beepbox that have more stuff then Beepbox. It can be used just like Beepbox. The features of Jummbox is the same of Beepbox's features, but Jummbox have more stuff to offer.
LMMS - Make music with a free, cross-platform tool