Sander over at NMA has written up a nice, concise, and straightforward history of the development of Fallout.
In response to the frequent misinformation spread about the basic
design of Fallout or the process in which it was made, NMA admin Sander
decided to search through old Usenet discussions with Tim Cain as well
as other more modern interviews with the core designers of Fallout 1 to
see what was the philosophy behind Fallout 2, the how and the why.
is fairly short, mostly because it doesn't contain any statement not
directly derived from a developer quote. It covers the GURPS/P&P
mechanics behind Fallout, the decision to go turn-based, details about
the setting and what inspired it, how the designers viewed RPGs, how
the game's release went and what was up with the lack of children in
the European Fallout 1.
Definitely worth checking out.
The History of Fallout
Thanks to Tannhauser for the tip.