Valve Hammer Editor 3.4 addon - Half-Life - Mod DB
Valve Hammer Editor - Valve Developer Community
I was using the hammer editor and noticed that ragdolls eyes stare at you all the time and its so creepy i kinda wanna stop messing with this map for now :
VHE] Valve Hammer Editor Video Tutorials file - Goldsource Data Base mod for Half-Life - Mod DB