There are not too many sites devoted to Arthur Koestler on the Web.

There are a few pages of sparse selected quotes (, not really interesting, and some other pages related to the historical meaning of Darkness at noon ( and of Koestler's life ('aiuto/daiuto404.htm)

Quite different from the other sites are the web of the Koestler Award Trust (, now quite outdated) and the web of the Koestler Parapsychology Unit at the University of Edimburgh ( To learn more about these institutions, visit their Webs or read the related page in Koestler's biography.

A quite interesting page is the one from Authologies (in french):

Yet another category of Web sites are the ones that present the full text of his The Thirteenth Tribe, often presented in a quite anti-semitic fashion or more simply in an anti-Israel mood (Hey, but if these jews aren't really jews, why do they say they want to return to Israel?)