Counter Strike 1.6

Counter Strike is a tactical first person shooter video game which originated from a Half-Life modification by Minh “Gooseman” Le and Jess (Cliffe) Cliffe.Counter Strike pits a team of counter-terrorists against a team of terrorists in a series of rounds. Each round is won by either completing the mission objective or eliminating the opposing force`

==> Counter Strike was developed first as a Half Life modification, and therefore named (Half-Life: Counter-Strike). The original version was a 3rd party Half Life modification, but since then it has grown into a commercial mod and later advertised as a separate game in itself. It still uses and runs on the Half-Life game engine and is based on its unchanged structure`