Within two weeks of releasing DOOM, we put the data structure used to build the game’s levels on the internet. Sharing that data made good on our promise. The decision to open our game up to the public was something that John Carmack and I felt strongly about. It was part of our core as programmers; we believed in sharing technology so that players could build their own creations and, ideally, lead to new improvements. We wanted and expected people to build editors, create new levels, make new sound effects, add new wall textures, and design new monsters. In fact, we looked forward to it!
