Livetraker Audio Midi Player - LiveTraker is a audio / midi / text player specifically designed for live performance on stage
Soundplant - Play sound files with the computer keyboard
Cue Player - Cue Player software for theater sound and lighting
CasterSoundboard - A soundboard for hot-keying and playing back sounds. (For podcasting)
JN Soundboard - An open-source hotkey soundboard program
iAC Studio - iAC Studio allows you to playback multiple audio tracks at one time.