QLab Free Version provides a powerful audio playback environment
The basic version of QLab is free and provides a powerful audio playback environment. For advanced users, licenses are available to enhance the audio features, as well as to add video and MIDI functionality.
* QLab 2 requires:
o Mac OS 10.5.2 or later
o QuickTime 7.3 or later
* Video playback requires that all graphics cards support Quartz Extreme and CoreImage.
http://figure53.com/qlab/download/