Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
Linux Show Player - Sound player designed for stage productions
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.
QLab - QLab, Live show control for Mac OS X.
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.
Trigger Audio and Video Playback - Audio and video cue player for broadcast and live performance.