Artificial languages are constructed languages, created by people to be used as a means of communication. Esperanto, Volapuk and Ido are three of the most well-known artificial languages. Esperanto is a language created in 1887 by L.L. Zamenhof, a Polish ophthalmologist, with the intention of being an international auxiliary language. Volapuk was created in 1880 by Johann Martin Schleyer, a German Catholic priest, and was intended to be a universal language. Ido was created in 1907 by Louis de Beaufront, a French linguist, as a reformed version of Esperanto.