Named Game of the Year by over 50 publications, Valve's début title blends action and adventure with award-winning technology to create a frighteningly realistic world where players must think to survive. Also includes an exciting multiplayer mode that allows you to play against friends and enemies around the world.
This Pack Contains Multiplayer Map Packs, SDK Tool Kits & Game Fixes.
Cool 4 Steam Client. . .
Quite possibly the best addon yet. Bringing back those days of looking for awesome models, skins, dlls, etc, etc..