Bosca Ceoil - A free, easy to use tool for creating music.
SunVox - SunVox is a small, fast and powerful modular synthesizer with pattern based sequencer (tracker).
Jeskola Buzz - Jeskola Buzz is an all in one digital audio workstation that allows you to edit music with the perfect blending by using modern tools and technology.
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.
Zynewave Podium - Podium is a modern digital audio workstation (DAW) for Windows.
MOTU Digital Performer - Get inspired, then refine your mix — all in a singular workflow.