Goldsource compilers

What engine is GoldSrc based on?
At its core, GoldSrc is a heavily modified version of id Software's Quake engine..
What is the difference between Source and Goldsource?
In summary, GoldSrc is the older engine used in the original Half-Life game and its expansions, while Source is the newer engine that was first used in Half-Life 2 and had more advanced capabilities..
Why is it called Goldsource?
Trivia.
The term "GoldSrc" comes from development of the Source engine.
A few months before the release of Half-Life, the Half-Life engine's source code was split into two branches: Src and GoldSrc.
The GoldSrc branch was the gold master version of the codebase, and would be used for the proper release of the game..
The engine has been officially abandoned in favor of the Source engine (except for minor maintenance updates) although the GoldSrc engine is still used by third party developers, mainly for mods.

Jun 3, 2023VIS (GoldSrc compiler) Visibility, often just shorted to VIS, was one of the sets of tools originally shipped with the Half-Life mod tools

What engine is GoldSrc based on?