Update:(9 Oct 2013) The Dark Mod 2.0 is now completely standalone, which means you no longer need to own Doom3 to play it! We have spent a tremendous amount of time and energy replacing all the sounds, textures, particle effects, and models that we had been using. Hopefully this will open up a whole new audience of people who didn't want to have to purchase a different game in order to try The Dark Mod.
The Dark Mod, is a total conversion mod for Doom 3, by Broken Glass Studios. The Mod is actually two separate projects. The main branch of the project consists of a Doom3 total conversion, while the second branch of the project is the editing application, "Dark Radiant", a completely rewritten version of the open source GTK Radiant editor. Primarily a toolkit for building Thief-like missions, the mod features equipment reminiscent of the Thief series, and modifications and additions to Doom 3's SDK and scripting to improve the physics, modeling, and make enemy AI work similar to Thief AI.
Two alpha demonstrations, Thief's Den and The Tears of Saint Lucia, were released to demonstrate how the Mod was meeting its goals. The first proper beta version, 1.0, was released in October 17th, 2009. Update v1.01 was released on March 12th 2010, and v1.02 was released on May 25th 2010. Version 1.07 is the latest release (Nov 27th, 2011).
Fan Missions for "The Dark Mod" are listed in this category.
The community has produced over 40 missions to date. Many updates to the interface have been made including in game mission downloading, massive AI improvements, new animations, vocal sets and more.
The map editor, Dark Radiant has also had a ton of improvements, but the most noticeable ones are the ability to create readable texts and pages directly in the editor via a GUI, and also the GUIs for the conversation editor and the stim/response editor.