“3D Realms Forum - Features of the DNF engine?” (2008年6月14日). 2012年6月14日閲覧。 “Unreal. I believe we branched off somewhere around the Unreal 2 time when they added static meshes. Since then we've redone the rendering 100% and it's a fully modern engine.”
Hackersho, Yu Yu (2010年9月3日). “Duke Nukem Forever hitting in 2011”. Gameinformer.com. 2011年2月18日閲覧。 “We now know that Gearbox started working on the game year ago”
George Broussard Allen H. Blum III (2010年9月3日). “Duke Nukem Forever Hands-on Preview (comment from George Broussard)”. 2011年2月11日閲覧。 “Triptych Games which continued the game for us through all of 2009 and into 2010 with Gearbox. Triptych is made up of 9 3DR employees who refused to let the game go and we found a way through the legal maze to keep them working on the game and to keep the game alive. They have been the development force for the last year that's made the game possible. What you see coming from PAX right now is what we originally made at 3DR with polish and additional work by Triptych and assistance from Gearbox”
