Historical Atlas of the Twentieth Century

Librarian Matthew White is behind this website, which features an astonishing array of demographic and political data in the form of a series of detailed and colorful maps.

HNN's Jonathan Dresner reports that the site has"some interesting alternate histories, as well, including the 'what if all the separtists won?' map, the 'what if Australia had been colonized by Muslims like Indonesia?' map, and the '20c Middle Earth' map (including the Hobbits' Autonomous Socialist Republic of the Shire)."