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.
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
Reaper - Reaper is a focused digital audio workstation (DAW) developed by Cockos. In the creation of the software, the digital audio technology company intended to make audio editing accessible to the masses.
Music Studio - Music Studio offers a complete music production environment for the iPad/iPhone/iPod touch with...
LMMS - Make music with a free, cross-platform tool
energyXT - With energyXT you can focus on the music, instead of becoming distracted by tons of features you don't need.