Serum - VST for FL Studio, Ableton Live, and many other VST supported DAWs. Heavily utilized in EDM.

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.

Surge XT - Open-source subtractive-hybrid synthesizer formerly sold commercially as Vember Audio Surge.

SunVox - SunVox is a small, fast and powerful modular synthesizer with pattern based sequencer (tracker).

Omnisphere - Piano, pad and synth VST for DAW's.

Cubasis - Cubasis is Steinberg’s streamlined, multitouch sequencer for the iPad.