Games - Doom 3

YouTube - Gaming Pastime - Doom 3: BFG Edition & Perfected Doom 3 v7 for PC Video Review

Maps

Phobos a three episode expansion pack.

Mods

OpenCoop
Zombie Slayer
Last Man Standing Coop

Sikkmod is a general enhancement mod for id Software's 2004 FPS: Doom 3 and its expansion pack: Resurrection of Evil. Its main purposes are to update visuals of Doom 3 to a more modern level.

Perfected Doom 3 was started as a simple tweak mod years ago. Now Perfected Doom 3 is more then just a tweak mod. It attempts to completely overhaul the entire game with new monsters, rebalanced weapons, rebalanced monster stats, better graphics, new gameplay features and much more.

Enhanced Militarized Zone - Running 1.3 Mods on Doom 3 Version 1.3.1 Some of the old single player mods for Doom 3 have never been updated to the final 1.3.1 release. This is usually because the mod team has disbanded, lost the source code or just can't be bothered. You can now play your old 1.3 mods on 1.3.1 using the new mod-helper mod “Run 1.3 on 1.3.1”.

EMZ is a multiplayer mod for Doom 3 that adds a whole host of options to the game to make it more fun to play, much more configurable and addresses many of the shortcomings of the standard game.

Source

Github - TTimo/doom3.gpl Doom 3 GPL source release.
GitHub - id-Software/DOOM-3-BFG Doom 3 BFG Edition.

Fabien Sanglard's Website - Doom3 Source Code Review

iodoom3 GitHub - iodoom/iod3

dhewm3 is a Doom 3 GPL source port, know to work on at least Windows, Linux, Mac OS X and FreeBSD. The goal of dhewm 3 is bring DOOM 3 with the help of SDL to all suitable platforms. Bugs present in the original DOOM 3 will be fixed (when identified) without altering the original gameplay. See also: GitHub - dhewm/dhewm3.
SourceForge - gbDoom3 is a fork of dhewm3 with a series of modernisations, performance improvements and an emphasis on being bug-compatible with vanilla Doom 3.
GitHub - RobertBeckebans/RBDOOM-3-BFG Doom 3 BFG Edition with soft shadows, cleaned up source, Linux and 64 bit Support.
eXistence/fhDOOM Modernized DOOM3/idTech4 engine: ported to modern OpenGL (core profile), enhanced visual effects, improved performance, improved editor, more to come.
GitHub - PJayB/DOOM-3-BFG-DX11 A port of Doom 3 BFG Edition from OpenGL to DirectX 11
SourceForge.net - Doom 3 Splitscreen Edition Currently buggy, this modification to the Doom 3 engine allows for cooperative gameplay with two players on the same computer. The first player uses a mouse and keyboard, while the second player uses a 360 game controller.
GitHub - omcfadde/dante idTech4 OpenGL ES2.0. See Oliver's Blog.
GitHub - djbozkosz/Doom-3-Phong-Shading Modified shader (ARB_program) for Doom 3 with per fragment specular reflection (Phong Shading).
GitHub - fabiensanglard/Doom3-for-MacOSX- This is a release that will actually compile on Mac OS X Intel. A fork of GitHub - doubledrones/Doom3-for-MacOSX-.

Github - geenz/doom3.gpl (dead link) This is a fork of the Doom 3 GPL release intended to get Doom 3 compiling, and running, on modern versions of Xcode. Some bits may work, other bits may not.
GitHub - badsector / Doom3-for-MacOSX- (dead link) This is a fork of fabiensanglard's Doom 3 for Mac OS X. It is modified to build properly under the latest Xcode and Mac OS X 10.7 SDK.

GitHub - KainoaLloyd/DOOM3-BFG-Architecture This demonstrates the Game Doom 3's software architectecture. Queen's University CISC/CMPE 326 Group Project.