ZynAddSubFX

ZynAddSubFX (also now called Zyn-Fusion) is a free and open-source software synthesizer for Linux, Mac OS X and Microsoft Windows. Version 3's new user interface was initially released under proprietary terms, but is now open source (though prebuilt binaries are still sold to fund development).

For sound generation it has three hybrid synth engines that combine additive, subtractive, Fourier and other synthesis methods. No external samples are used to produce the sound; everything is done by synthesis. The synthesizer has effects like reverberation, echo, chorus, distortion, equalization and others, and supports microtonal tunings.

The original author of ZynAddSubFX is Romanian programmer Nasca Octavian Paul. The project was started in March 2002 and the first public version (1.0.0) was released on September 25, 2002. Since 2009, the new maintainer is Mark McCurry.