From Half-Life Library

Terror-Strike was the original name for the now Source engine based game, Left 4 Dead. The original idea of Left 4 Dead was made possible by bot experimentation in Counter-Strike: Source through Turtle Rock Studios.

Michael Booth, creator of Turtle Rock Studios (now Valve South) started playing with the concept large numbers of bots (with knifes) for Counter-Strike: Source against human players. Afterward, during 2006, the game was later referred to as a "new Source-based title" in a Steam press release. This later developed into a large amount of artificial intelligence controlled zombies that we now see in Left 4 Dead. The development process for Left 4 Dead (still Terror-Strike at the time) started in early 2005 with the final version of the game being released on November 18, 2008.

External Links