Valve made Counter Strike. Hammer is an Editor to create maps.
CS1.6 Counter-Strike Surf Settings
sv_stepsize 550 sv_airaccelerate 100 sv_gravity 800 fps_max 100
Hammer tutorial: http://counterstriketutes.blogspot.com/2009/04/how-to-make-counter-strike-16-map.html#ixzz1RgXPZk4w hammer_tutorial.pdf
Mit Crafty kann man CS1.6 Maps extrahieren.