Elias Papavassilopoulos

Elias Papavassilopoulos (alias "CaveMan") was a notable member of the early Doom community, particularly through participation in Usenet in. He was the first person to decipher the encryption used on the Doom cheat codes in the game's executable file, publishing the results as a mostly complete list of the cheats to the group on December 15, 1993. He did this by using a 32-bit executable disassembler for which he created himself, using it to locate and reverse engineer the  routine in the DOOM.EXE executable file. Managing to do this so quickly impressed id Software programmer Dave Taylor, who was responsible for implementing the cheat codes and their method of encryption, and Dave sent Elias a t-shirt he was wearing at the time in exchange for an explanation of how it was accomplished.

Elias later participated in creating The Unholy Trinity, a significant early PWAD recreating the campus of, which was named one of the Top 100 WADs of All Time by Doomworld.