Show Cue System - Show Cue Systems
QLab - QLab, Live show control for Mac OS X.
Linux Show Player - Sound player designed for stage productions
Resolume - Resolume is an application for live video performances.
Smode Studio - Realtime compositing and display for live shows, concerts and events.
CasterSoundboard - A soundboard for hot-keying and playing back sounds. (For podcasting)