via http://www.dcemulation.org/?title=Main_Page

Isotope Studios, the developer behind upcoming 3D horror games Scourge and Hypertension: Harmony of Darkness, has released the source to its custom 3DGE game engine. The source, along with all of the necessary documentation, is available at the 3DGE SourceForge page. Additional support can be found at Isotope's forums.

According to Isotope, Dream3DGE is a fully 3D game engine built on id Software's DOOM engine. From the SourceFoge page, features include
- stable, fast OpenGL rendering system with support for Quake 2 and 3 models
- splitscreen local networking for cooperative and deathmatch play
- SEGA Dreamcast portability (currently under /source)
- powerful DDF, RTS, and COAL scripting to make your DOOM mods come to life

Isotope developed 3DGE for Hypertension, and it is being released to the public in the hope that it will catch on and spur a new generation of 3D Dreamcast projects.