Cavalary: Pardon? Manual lookup is DRM, keys are DRM, disk checks are DRM, those technologies Gudadantza listed are DRM. DRM existed before the Internet, so no way it "always has been online since the term exists".
As for those GOG games, which have indeed existed since GOG launched, the keys are only for multiplayer, which was why GOG had its no DRM stance just for singleplayer.
neumi5694: No, it's not. That's physical copy protection. The term "digital rights management" was not used back then.
The term DRM was introduced in the mid 90s, when digital audio media became a thing (in your link 1996 is named) and we both know that the internet went commercial 1990, but existed way before that. Also we had copy protection long before that. That was not DRM, that was copy protection. One could only copy and use the software, if he had the manual or code wheel or whatever. No licence management was involved. The game was a tangible product sold as such, not just as licence to play it.
But ... I admit: I forgot the sort of unlock key that was used for shareware and was sent via physical mail or telephone.
Still that key was no good for any kind of rights management, since you could still share it with others and not have any problems to use it multiple times. That could only be prevented once online verifications were in place.
Anyway, it has already been stated that these games and vendors
will be listed on the front page, so you either live with it or don't. It won't make a difference.
Strictly DRM or not in the modern definition of the term it was a way to protect their rights based in a license, because, yes, inside the CD there was a digital program and you had a license over the products and info about what you could do with it. It was a way to evade piracy as the modern DRM systems are. Just to define one of its labors.
Also one of the origins of GOG, in general, was to maintain their installers free of this systems, don't you think? And I am sure they considered/defined it as a wide label, DRM.
If it is not DRM it is very close, strictly legal definitions aside.
I am referring to the practice way of things, but well, whatever. If the real definition is another, ok, you have the point.
Greetings