The Demon Summoning Program was first featured in Digital Devil Story: Megami Tensei and plays an important role in the games it appears in as it allows for humans with the capability to utilize demons in battle as well as storing them away for later as data. It's usually utilized via portable computers called COMPs due to its convenience. Typically, the Demon Summoning Program works by using code to replicate a summoning ritual. This was elaborated on twice in Digital Devil Story and Devil Survivor.