Weimar World started out as an Alternate History Challenge in the Discussion forum to create a plausible timeline in which the German Republic formed in Weimar, Germany in 1919 survived to the present day. It then was selected as the topic for joint efforts at developing a timeline between AH.com and OTL.com. The project attracted several commentators and contributors, to the point that the timeline which allowed for moderate levels of butterflies grew to describe the 100 year history of an entire world from the founding of the Weimar Republic in 1919 to its centennial in the year 2019. With the expanded scope of the timeline, it came to be referred to as Weimar World.
The timeline actually does not diverge from OTL until 1920, when the Kapp Putsch is avoided. This leads to Paul Emil von Lettow-Vorbeck remaining in the Reichswehr and aborts the subsequent development of the Ruhrkampf. Very quickly, we begin to see less radicalized politics in Germany compared to OTL.
There is also a quasi-butterfly effect of the aborted Kapp Putsch in that Adolf Hitler is revealed shortly after as a Reichswehr spy and thus is driven out of the nascent German Nazi Party and returns to Austria. Once there he slowly rebuilds his reputation, this time in the Heimwehr, and goes on to become the leader of the Pan-Germanist faction in the Heimwehr.
Other early important changes include a longer tenure as Chancellor for Gustav Stresemann and no death from appendicitis for German President Friedrich Ebert.
In 2007 it won a Turtledove for best Shared Worlds/Collaborative Timeline.