Eh, I don’t really think that this is an “or” situation. I think that this is an “and” situation. The last time that I set up Xash3D FWGS, I had to copy files from the version of Half-Life that I own on Steam into a different folder so that those files could be loaded by Xash 3D FWGS. I haven’t tried Xash 3D FWGS in a while, but it looks like you still have to do that [1]. Also, are you sure that the Steam version of Half-Life is Windows only?
[1]: <https://github.com/FWGS/xash3d-fwgs/blob/f0342763547d9bcf486...>
What's the point of using this xash thing then?
For whatever reason, Valve doesn't want to open source the engine so some people have taken it upon themselves to build a reverse-engineered engine (which now runs on Android, in the browser etc).
It’s open source and runs on all kinds of platforms. Original HL1 runs on old Windows and IIRC DOS. Nowhere else
Valve updates HL1 every few years so it runs on contemporary platforms. DOS was ancient history by the time HL came out, you might be getting it mixed up with Quake1
> Also, are you sure that the Steam version of Half-Life is Windows only?
You're right! It looks like Linux has a native build too. Apparently the Windows version, through Proton, runs better though (not that it matters).