The Straad Players

As yet untested by the Straads but it is a free download and looks really promising. Check it out here

Here's what they say:

Celtx is the world's first fully integrated solution for media pre-production and collaboration. It replaces old fashioned 'paper, pen & binder' media creation with a digital approach to writing and organizing that's more complete, simpler to work with, and easier to share.