"Diary of a Camper" is built on the ability to record gameplay, which appeared earlier in id Software's 1993 computer game "Doom". Using this feature, players could efficiently record game events, rather than the rendered video itself, and later replay them in real-time through the game engine. "Doom"s successor, "Quake", offered new opportunities for both multiplayer gameplay and customization, while preserving the demo recording ability. In the book "Machinima", Kelland, Morris, and Lloyd stated that multiplayer games became popular, almost a sport, and demo files of matches were recorded and studied. Paul Marino, executive director of the Academy of Machinima Arts & Sciences (AMAS), used a different analogy: "Players began to record deathmatches with a more cinematic flair... "he viewpoint of the player became the viewpoint of a director.""