> HL's engine GoldDrc was originally a mod for Quake.

GoldSrc is based on Quake 1 code with valves own modifications and a little Quake 2 added in, if I remember correctly. I wouldn’t call that a “mod”, they bought a commercial license for the engine and made a game with it.

You’re trying to use this to say that valve are unoriginal? I really don’t think that’s a criticism you can lob at the half life series.