Counter Strike Addon to Doom???

[Reese]

As i was seaching on youtube to see how to put doom on my ipod, i found a video for an addon to doom that was the game counterstike. It supprised me because iv never herd of this anywhere else??? The game looked like counterstike and the instructions werent terrible but not great and didnt seem trustable enough to try it. If you please could, check it out and let me know if youve herd of this or if its safe to try...(i also found the same thing for halo, is this just all a cruel trick???)
Here's the youtube link:
http://www.youtube.com/watch?v=2u9TLzcUv9w

[GodEater]

Use the forum search feature. This Doom addon has been discussed many times before.