Half-Life Opposing Force
You have found the way to Opposing Force on Half-Life:
Sierra: Half-Life: Opposing Force - Official site includes game overview, news, media, support, forum, demo download, and online ordering.
CNET - Includes a free demo download and user opinions of the game.
GameGuide.com - A complete game guide including first-person shooter basics, weapons descriptions, walk-throughs, cheat codes, and easter eggs.
Justice for all [JFA] - Includes screenshots, pictures, profiles, and downloads.
Planet Half-Life: Opposing Force - Walkthrough, tips, downloads as well as strategies for both the single player and online multiplayer version. Help build the largest human-edited directory on the web.