Pure Data - Pd (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical...
miRack - Eurorack-style modular synthesizer for iOS.
VCV Rack - A cross-platform modular synthesizer.
Voltage Modular - Virtual modular platform designed for flexibility and pro sound
SuperCollider - A real time audio synthesis engine, and an object-oriented programming language specialised for...
SynthEdit - Visual programming software to build your own synthesizer.