Bosca Ceoil - A free, easy to use tool for creating music.
ZynAddSubFX - ZynAddSubFX is an open source software synthesizer for Linux, Mac OS X and Microsoft Windows.
Renoise - Renoise is a digital audio workstation.
Qsynth - Qsynth is a simple Qt4 application wrapper for the ...
Zynewave Podium - Podium is a modern digital audio workstation (DAW) for Windows.
Surge XT - Open-source subtractive-hybrid synthesizer formerly sold commercially as Vember Audio Surge.