[AndrewOMartin]

Gamers includes people who play Doom. It's reasonable to think a few of those players will ask "Why does this have from the 90s have such an excellent, creative and enjoyable scene when tons of games since have been forgotten?"

The answer, at least partially, lies in free tools, engines, and community content.

[simonh]

The only reason the engine can be free nowadays is that it has near zero commercial value to the IP owners. If the lesson is that for a libre game to survive and prosper at the mass market level being worthless is an important enabling factor, that’s not a great conclusion to come to.

Anyway Doom has this great community around it not just because the tools are free, thought that’s a an important enabling factor, but due to its cultural significance to gamers and games developers.

[pilaf]

id Software has a history of releasing the source code to their engines ~4 years after their initial commercial release:

Doom released in 1993, its engine was open-sourced in 1997 (4 years).

Quake released in 1996, its engine was OSS'd in 1999 (3 years).

Quake II released in 1997, OSS'd in 2001 (4 years).

Quake III released in 1999, OSS'd in 2005 (6 years).

Sure, in most those cases they were at least 2 generations of their own tech ahead when releasing source code, but considering how they were at the cutting edge of game development at the time, arguably those engines still held considerable value at the time and far from worthless.

[Ekaros]

Or that it is pretty good game and has the brand. The variants by my understanding aren't so different from it in those aspects, but they don't have similar scene think of Hexen and Heretic. And then the third party titles, how many remember or play those?