Heretic is a fantasy first-person shooter video game created by Raven Software, published by id Software, and distributed by GT Interactive in 1994. It was made available on Steam on August 3, 2007.
Using a modified Doom engine, Heretic was one of the first first-person games to feature inventory manipulation and the ability to look up and down. It also introduced multiple gib objects spawned when a character suffered a death by extreme force or heat. Previously, the character would simply crumple into a heap. The game used randomized ambient sounds and noises, such as evil laughter, chains rattling, distantly ringing bells and water dripping in addition to the background music to further enhance the atmosphere. All music in the game was composed by Kevin Schilder. A sequel, Heretic II, continuing the story, was created in 1998.
Source Ports:
HHeretic
This is a new release of Dan Olson's Hacked Heretic, by the authors of Hammer of Thyrion.
Doomsday
The Doomsday Engine is a source port with support for Doom, Heretic, and Hexen. It runs on Linux, Mac OS X, and Windows, and is presently developed by Jaakko Keränen (skyjake) and Daniel Swanson (DaniJ). Former developers include Jamie Jones (Yagisan).
Doomsday itself is a multi-game supporting engine and developed along with it are numerous plugins; e.g. game plugins which are necessary to actually play a game using it. Four official plugins are being developed by the core deng team alongside the engine: jDoom, jHeretic, jHexen and recently, jDoom64.
ZDoom (and its derivatives)
ZDoom is a source port, originally based on ATB Doom and NTDOOM. It has since added full support for all commonly-used Boom additions, Heretic, Hexen, Strife and Chex Quest. It has added many additional features, including slopes, uncapped framerate, and z-clipping. The source code is maintained by Randy Heit and Graf Zahl. The most recent official version is 2.5.0, but many in the community use the development versions. The large number of features supported by ZDoom made it the port of choice for several independent game projects, notably Foreverhood, Action Doom 2: Urban Brawl, Chex Quest 3 and Harmony.