The 1966 film "Incubus" was made in what language?

"Incubus" is a 1966 black-and-white American horror film filmed entirely in the constructed language Esperanto. It was directed by Leslie Stevens, creator of The Outer Limits, and stars William Shatner, shortly before he would begin his work on Star Trek. The film's cinematography was by Conrad Hall, who went on to win three Academy Awards for his work on the films "Butch Cassidy and the Sundance Kid", "American Beauty" and "Road to Perdition". The use of Esperanto was intended to create an eerie, other-worldly feeling, and Stevens prohibited dubbing the film into other languages.

The premiere of "Incubus" took place at the San Francisco Film Festival on October 26, 1966, where, according to producer Taylor, a group of 50 to 100 Esperanto enthusiasts "screamed and laughed" at the actors' poor pronunciation of the language. Partly because of its Esperanto dialogue, and partly because of the scandal of actor Milos Milos taking his own life and that of his girlfriend Carolyn Mitchell, Taylor and Stevens were unable to find any distribution for the film except in France, where it premiered in November 1966.

"Incubus" was considered a lost film for many years. When producer Anthony Taylor attempted to prepare Incubus for home video release in 1993, he was told by the company that stored the negative, film elements, and prints, that all were missing and presumed to have been destroyed in a fire. A new master copy was created frame to frame.