FL Studio - Image-Line's FL Studio, now on it's 12th version, is a well-known music production suite and the most popular beat processor on the market, due no doubt to its longevity. Read more about FL Studio.
ReCycle - ReCycle is a creative tool that helps you make the most of your grooves.
GarageBand - GarageBand is a fully equipped music creation studio for Mac
VICE - Bring loops to life with the loop slicer plugin for Mac and Windows.
Caustic - Caustic is a music creation tool inspired by rack-mount synthesizers / samplers rigs.
Egoist - Powerful groove instrument with built-in sequencer, audio slicer and effects.