Heh, cool. I feel special.
Well, I would recommend looking at our code. Although the actual game engine portion of the code is not working at the moment, the shooting and some of the old movement code is the same as seen in that video.
If you are looking for a completed FPS engine, it might not be the thing, though. Not yet, at least...
If you learn anything from the OpenFPS code, the most valuable lesson is: code in modules. If we had all our code (over 8000 lines) in one source file, it would be a nightmare. Modules let everything be organized neatly and in shorter files.