Risen3D is a fork of the Doomsday Engine (based on Doomsday 1.7.8, originally released on March 15, 2003) by Graham Jackson. It was originally known as Boomsday as it existed solely to add support for the additional editing features of Boom to the jDoom plugin of the Doomsday Engine. The project was renamed to Risen3D when the author decided to no longer incorperate changes made to the main Doomsday source repository.
On September 9th, 2006, the project was terminated by the Risen3D team. This was in response to repeated requests made by various prominent members of the Doom community, who asked them to release the source code, as required by the GNU GPL under which the Doomsday engine is licensed.
On October 6, 2006, the project was brought back and the source code released.