Hydrogen - Hydrogen is an advanced drum machine.
UVI Falcon - Sampler/synth hybrid instrument
drumbit - A very easy to use drum machine.
Pianoteq - Pianoteq is a virtual piano that runs on your computer.
HTML5 Drum Machine - The HTML 5 Drum Machine is a browser-based drum machine inspired by the classic Roland TR-808.
LinuxSampler - LinuxSampler - free, open source pure software audio sampler with professional grade features.