Qsynth - Qsynth is a simple Qt4 application wrapper for the ...
VirtualMIDISynth - VirtualMIDISynth is a software MIDI synthesizer implemented as a Windows multimedia user driver...
OpenMPT - OpenMPT is a popular tracker software for Windows.
ZynAddSubFX - ZynAddSubFX is an open source software synthesizer for Linux, Mac OS X and Microsoft Windows.
MilkyTracker - MilkyTracker is an open source, multi-platform music application for creating .MOD and .
Surge XT - Open-source subtractive-hybrid synthesizer formerly sold commercially as Vember Audio Surge.