Apprehension
- Includes stories, speculation, and theories. Basic help with the game and links to walkthroughs.
- http://www.btinternet.com/~rideflame/HalfLife/HalfLife.html

Pro-HL
- Contains maps, models, mods, patches, tweaks, tips, leagues, clans, tools, and demos.
- http://www.pro-hl.com/