Arx Libertatis LicenceGNU General Public License, version 3.0Kindsource port, video gameBased onArx Fatalis
DelphiDoom Implemented inDelphiLicenceGNU General Public License, version 2.0 or laterKindsource port
Doomsday Engine Implemented inC, C++LicenceGNU General Public License, version 2.0 or laterKindsource port
International Doom LicenceGNU General Public License, version 2.0Kindsource portBased onChocolate Doom, Crispy Doom
Ioquake3 Implemented inCLicenceGNU General Public License, version 2.0Kindgame engine, free software, source port
PrBoom LicenceGNU General Public License, version 2.0 or laterKindfree software, source portBased onBoom
PsDooM LicenceGNU General Public License, version 2.0Kindfree software, source portDeveloperDennis L Chao