EDGE (Enhanced Doom Gaming Engine) was a collaborative Open Source project based upon the Doom source code. EDGE is derived from the DOSDoom source port. The first official version of EDGE was released on June 20, 2000. The final version of EDGE, version 1.35, was released on April 9, 2011.
The most attractive feature of EDGE is its DDF system. DDF describes all game behaviour inside text files external to the executable file. As a result, it is popular among modders who use the extensibility to add many new weapons and features with many fewer of the limits present in other source ports. With DDF, for example, it is possible to create monsters which can possess multiple missile and melee attacks, or create custom pain and death states for monsters when hit by specific weapons or projectiles.
EDGE includes ports to many popular operating systems, including MS-DOS, Windows, Linux, BeOS, and Mac OS X. At one time EDGE supported both software-rendered and OpenGL hardware-accelerated versions; as of version 1.29 beta 1 and beyond, however, it no longer updates support for the software mode, as the team decided that working on two separate versions of the same port was too time consuming.
On April 9, 2011, EDGE was discontinued by the author, effectively ending development. Three days later, a new group of authors forked the port and called it 3DGE, releasing the first binary. The latest version is 1.36.3a, released on June 21, which includes new features, such as MD3 support for models. The group plans on adding a video decoder for external cinematics, split-screen support, polyobject support, and networking.
- Support for up to 64 defined weapons at once.
- 16 Ammo types: BULLETS, SHELLS, ROCKETS, CELLS, and AMMO5 to AMMO16. (AMMO1 to AMMO4 can be used as aliases for the 4 main ammo types.)
- Extrafloors feature allows modders to create submergible liquids, room-over-room, or catwalks, as well as vertically moving platforms not embedded into the floor.
- Four armor types: GREEN (33% reduction), BLUE (50% reduction), YELLOW (75% reduction), and RED (90% reduction).
- GL Nodes allow better 3D rendering of both existing Doom levels and newer levels.
- Mipmapping, Smoothing, and Dynamic Lighting.
- Automap can be made to be stationary instead of rotating with the player's facing angle.
- Automap can also be applied as a secondary layer over the normal viewing screen opposed to replacing it, allowing the player to fight enemies and keep track of their position at one time.
- Weapons can have secondary attacks. Weapons can also be made to be manually reloaded or have idle stats as well.
- Support for MUS, MIDI, and Ogg Vorbis music formats. CD support was dropped.
- DDF files allow the editing of many features (such monsters, attacks, and levels).
- Sprites can be viewed from 16 angles (see Sprite).
- RTS scripting format includes an option known as "Start_Map ALL" that allows global scripts to be created that affect all maps in the game without copying the script under each individual map.
- JPEG, PNG, TGA Hi-res textures.
- Sliding doors.
- MD2 Model Support
With the 3DGE fork, the port gained support for MD3 models, extended DDF features (such as the falling sound), and bugfixes.
EDGE also brings its own unique set of popular add-ons to the Doom community. Although some dislike EDGE for its perceived instability, the following mods have in one way or another made their mark on the community.
- Don's Challenge — Created by Cory Whittle, Don's Challenge is a 3-episode modification based around the supernatural adventures of Don P. Tello, a veteran cop who is summoned into Hell by Mortis, the incarnation of Death, to challenge thousands of hellspawned creatures that his soul might be deemed worthy by her as a vessel. At the end of Episode 1, Don transforms Mortis into a cat. However, her brother Fate summons Mortis to Hell and takes Don with her. In the third episode, Don and Mortis return to Earth, only to find it overrun by Demons and Don's own family dead; Don and Mortis attempt to take vengeance for the deaths. This mod became popular due to the use of new monsters, weapons, and levels. One weapon (cigarettes) could even be used to heal the player. Another weapon (Booze) could be used to increase armor value, but took away a small portion of health as well. As of now, only one episode is fully released, but Episode 2 is reportedly on the way.
- Immoral Conduct - Created by Cory Whittle, Immoral Conduct is a weapons modification for both EDGE and ZDoom (although the ZDoom version does not have as many features as its EDGE counterpart). The EDGE version contains the following: Knife, .45 Pistols, Stock 12g Pump Shotgun, Customized Pump Shotgun (fires 'slasher rounds'), 12g Hand Cannon, 9mm Uzi SMG, Fragment Hand Grenades, 40mm Grenade/Tear Gas Gun, Assault Rifle with M203, Infantry Rifle with Bayonet, Minigun, 12g Sawed-off Shotgun, Beretta 9mm Pistol, Chrome Magnum Revolver, Sentry Turret Kit (summons helper turrets to attack enemies), Gas-Powered Chainsaw, Remote/Proximity Satchel Charges, and Marking/Visibility Flares. New items included a 50% medikit and Nightvision Goggles. New helper monsters included the Marine Corporal and Marine Private. Monsters have also been modified (for example, the Baron of Hell's blood is green), and shells are ejected from weapons. It is a partial conversion, sometimes mistaken for a total conversion, and in Whittle's words, "With my stuff, you have all the millions of user-made Doom and Doom II levels at your disposal to be enhanced with new weapons and items."
- Covert Ops — an EDGE version of Twilight Warrior. It has many features, such as new weapons and interesting scripts.
- QDoom (Quake Doom) — Created by Marc "Fanatic" Pullen, QDoom is a total conversion of Quake to Doom.
- EBDoom (Earthbound Doom) - Created by Baron of Sigma, this modification has generated mixed opinions. It is not a complete game, and many consider it more of a "monster modification" since roughly 100+ different species of monsters exist, most of them imported and emulated from Heretic, Hexen, Duke Nukem 3D, Shadow Warrior, and Blood, and 'evolved' versions of existing game monsters, such as Chainsaw Zombies, Gold Liches, and Elder Mancubi. The game also appears to use a near-perfect emulation of the Sigil from Strife as an easter egg weapon. In addition, the player has hit points instead of a health percentage, and can take much more damage than the common version of Doomguy. There are also several 'helper' characters based on the heroes of many of the Doom-engine games, including Doomguy, Corvus, and the player classes in Hexen. Certain bosses are also among the few in many modifications to have over 50,000 HP, with at least one boss having over 6,000,000 HP. The weapons are more 'mystical' and energy-based, with few traditional Doom-style weapons. Another unique feature in EBDoom is that all melee attacks used either by the player or other monsters/allies can inflict "critical hits" up to 4x damage at times, as in an RPG. Despite the community's mixed opinions of the mod, it is often used as a resource wad by other modders who want to quickly import foreign monsters into their own mods (as the author appears not to mind this). It is also one of the three mods in the Doom community to use Hissy as a central plot player, and makes many references to another EDGE mod known as Cacodemon Squad. This modification was last updated at 6.56 on January 12, 2006.
- GoldenEye Doom2 - A fairly large in-progress TC. Featuring a load of weapons in both single and multiplayer maps. Multiple versions are available: A single player DEH version compatible with Doom Legacy and Zdoom 1.22. Multiplayer levels for standard Doom2. An enhanced single player EDGE 1.27+ version. The Edge version contains the following weapons: punch/kick, Knives, Watch lazer, _Soviet_Tank_, Silencedable PP7, Dostovie, Cougar Magnum, Automatic Shotgun, pathetic Klobb, Duestch, Zmg, KF7, Sniper Rifle, Ak47, Moon Raker Laser, RCP-90, Golden Gun, Golden PP7, Rocket Launcher, and Gernades. Most of the weapons have alternate firing modes and some weapons can be dual-wielded.
- Cold Hard Cash - An unique weapons mod offering a larger variety of weapons. Cold Hard Cash's spin on the weapons mod is that instead of just finding weapons laying around or dropped from enemies, the player must mug monsters for money to use at special weapons dispensers, which replace the original weapons, and sometimes artifacts and appear in their place. An example is that the Chainsaw is now a dispenser that allows the player to buy a Knife, a Crowbar, and other melee-type items. Most dispensers have a special offer on it, usually an upgrade to an existing weapon, which requires the said weapon in question to be held by the player before they can use it. It is also the first EDGE mod to use the "Start_Map ALL" RTS function, introduced in the 3rd release candidate of EDGE 1.29, which allows the same scripts to be usable on all maps instead of having to add the same ones to each map individually.