Much of Half Life 2's popularity can be traced directly to Valve's Source engine upon which it is based, along with CounterStrike: Source, Half Life 1: Source, Day of Defeat: Source and Vampire: The Masquerade to name a few. The Source engine is set to spawn even more fantastic games and mods which will continue the Half Life tradition of timeless user-made mods such as Counter Strike. This engine is both powerful and flexible, and just like other recent innovative game engines such as those of Far Cry and Doom 3, this one has plenty of scope to tinker, tweak and customize to your heart's content.



Link: TweakGuides