"The World of Darkness (or WoD) is the name given to three related but distinct fictional universes. The first was conceived by Mark Rein-Hagen, while the second was designed by several people at White Wolf Gaming Studio, which Rein-Hagen helped to found. The first two World of Darkness settings have been used for several horror fiction-themed role-playing games that make use of the Storytelling System. The third, Monte Cook's World of Darkness, includes only a single product. It is also the setting for White Wolf's Mind's Eye Theatre, a live action roleplaying game based on the core games."
Source: Wikipedia, "World_of_Darkness", available under the CC-BY-SA License.