I had the same Captcha system when I tried logging in to my Sony Playstation account as well a couple of days ago. Did eventually give up because it was basically unsolvable. Who would even want to implement a system like that?
I work for a movie production company and have been thinking of creating something similar - especially the collaborative and versioning feature as in github for screenwriting. If you like I could ping you via E-Mail as well, since there are some features crucial for (at least our) workflow. Revision aka colored (replacement)pages, excerpts for set dressers etc.
But so far it looks really great and I hope it'll be able to replace Final Draft at our company someday.
Very nice. I was recently look for something similar, but with support for markers (eg. add marker "explosion" to video XY at 2:14). Do you plan to implement such feature?