Boy, this archive is huge so this credits list could stretch on forever and I would still never get everybody who contributed something.
I'll just put down the contributors I remember.

- Valve Time
- Combine Overwiki
- Marphy Black
- Barnz
- Theuaredead
- Various Valve employee portfolios
- /r/HalfLife community
- GeckoNZ
- Joebama
- Half-Life 2: Raising The Bar
- hl2-beta.ru
- AciD
- The Dhel
- Talonbrave.info
- Pfc. C. Spaceman
- Valve News Network
- Magic Nipples
- AEX10
- liblung