Fallout: Van Buren
Fallout 3 - Van Buren
Van Buren was the codename given to Interplay and Black Isle's eventually cancelled Fallout 3.
On May 3, 2007, the tech demo of Van Buren was leaked to NMA, giving us a glimpse of what might have been.
You can try it for yourself by downloading Van Buren here.
There have been several attempts by the Fallout community to recreate Black Isle's vision of Fallout 3, using the Fallout 2, Fallout Online, and even Unreal and Unity engines, however, none of them have seen the light of day.
The Van Buren Design Documents available here formed the basis of these attempts.