To be honest, I've never bothered with screenwriting software before this. Seriously, why bother when I can set three tabs and be done with it. But CELTX is so amazingly loaded with features that it's worth it. You can intergrate storyboards and do script breakdowns with a few simple clicks. I'd have to go back through the press release, but I'm pretty sure the new version includes features for documentarians.
Did I mention before it's free?
take care,
Allen