The Dark Mod team has just released a new version of their Radiant-based editor for Doom 3, and more importantly, their own mod.
Massive improvements have been made since development started: a good deal of the code has already been refactored, improved or fully replaced by superior code. Highlights include the new or improved browsers for textures, models and skins as well as sound shaders. Texture Manipulation tools have been vastly improved and make seamless texturing a matter of seconds. A completely new U/V editor for patches is also included.
So go to the Dark Radiant page at Sourceforge for the changelog and to download the latest version.