VCV Rack - A cross-platform modular synthesizer.
SunVox - SunVox is a small, fast and powerful modular synthesizer with pattern based sequencer (tracker).
Pure Data - Pd (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical...
FamiStudio - FamiStudio is very simple music editor for the Nintendo Entertainment System or Famicom. It is designed to be easier to use than FamiTracker, but its feature set is also much more limited.
Voltage Modular - Virtual modular platform designed for flexibility and pro sound
MOTU Digital Performer - Get inspired, then refine your mix — all in a singular workflow.