With the success of the AI systems of Left 4 Dead, we've been continuing to develop these technologies to create new kinds of game experiences. Team Fortress 2 is an excellent "sandbox" for explorations of this sort, and we've been quietly doing so for much of this last year. Some of the results of these explorations are TF "bots" — AI-driven player proxies with simulated humanlike senses, reaction times, and tactics. Although the TFBots are not yet complete, they play a pretty decent game of King of the Hill.
We thought you might enjoy testing your skill against these work-in-progress digital killing machines.