The program listed in the link is a program designed to sync audio over a movie, mostly designated for fan made commentary (seen here http://www.sharecrow.com/search.html ). Some of the fan commentary is really great, some... well, can be a bore. The idea came when someone asked, "does Dark Side of the Moon really sync with Wizard of Oz?"
What you do if you want to try it out:
First, download and install the software.
Second, download a commentary that you own a movie for.
Then, open Sharecrow, and choose the button that says "open profile." Pop in the DVD and hit play in the sharecrow system. Then under the profile window choose file -> create crow. Then click on the first chapter that you're accessing, and hit add the downloaded audio file.
Some of these are completely worth it. Others... are a waste of time. And the majority of them are free.