Vodun is a Gbe word. It names the powers addressed in Fon and Ewe practice, and it travelled with the people taken from this coast into the Atlantic trade. The consequences are visible across the Americas: Haitian Vodou takes its name and a large part of its liturgical vocabulary from here, and elements reached Louisiana and, in mixed forms, Brazil and Cuba, where Yoruba material from further east is generally the larger component. What crossed was not a fixed system. People were taken from a region with many local cults, many priesthoods and no central authority, and what they rebuilt in the Americas was shaped by who survived, who was enslaved alongside them, and what could be practised without being punished for it. The religion is living on both sides of the ocean and is not a survival on either.
Vodun in Benin has recognised public status and an annual national observance, and Haitian Vodou has its own priesthoods, its own houses and its own authorities. The atlas describes both and instructs in neither. Where a practice belongs to initiates it says so and stops there, which is the correct treatment of an initiatory tradition with living custodians. The English word voodoo, with its long career in American film and fiction, comes from the same root and names nothing that anyone practises. The atlas uses Vodun for the West African tradition and Vodou for the Haitian one, which is how their own practitioners write them.