Left4Dead411.com has a 10 minute video presentation made by Gabe Newell on
the making of
Left 4 Dead. This was originally only seen by members of
the press at this year's E3, and the presentation is accompanied by an extended
version of the E3 trailer from the upcoming multiplayer zombie game. Word is:
"Gabe goes into detail on many aspects of the making of Left 4 Dead, including
their goals in development, the what and why of the AI Director, all about the
monsters including animation, physics and AI, and also all about the world
including graphics and lighting technology."