Recently id Software released the source code for Doom 3:BFG edition, thought it was a good thing to make a mirror of their source codes.
This source codes are dated 28-11-2012, get newer version and possibly new source codes at Github
id Sources 28-11-2012
72.8 MiB - 470 downloads
In the video all I noticed was the lower fov.
Yep i agree the 2 versions seems very similar..