[yolesaber]

I know this is an utter troll, but I think it is worth broadcasting to any HN member that DOOM is a notable feat of software engineering: not only did Carmack invent and perfect a wide variety of technologies, they also included what was the first seriously adopted modding kit that lead to a lot of people being introduced to game modification and programming.

[fdej]

Doom did not include a modding kit. All utilities were made by fans. Modding was easy in part because the engine had been designed to load all game content from separate, easily modified .wad files. (The rampant popularity of the game itself also helped pave the way for a modding community, of course.)

[eco]

That's not actually true. Carmack uploaded the source for the level editor and utilities for modders to use. The modding community just made much better and easier to use tools. .wad files were also created specifically to encourage modding and make it non-destructive.

Excerpt from Masters of Doom:

> Though Carmack and Romero were intrigued and inspired by these actions, they were concerned over the destructive quality of the mods. Players had to erase the original Wolfenstein code and replace it with their own images; once a Nazi was changed into Barney, there was no way to bring the Nazi back quickly. For Doom, Carmack organized the data so players could replace sound and graphics in a nondestructive manner. He created a subsystem that separated the media data, called WADs (an acronym suggested by Tom Hall, it stood for Where’s All the Data?), from the main program. Every time someone booted up the game, the program would look for the WAD file of sounds and images to load in. This way, someone could simply point the main program to a different WAD without damaging the original contents. Carmack would also upload the source code for the Doom level-editing and utilities program so that the hackers could have the proper tools with which to create new stuff for the game.