An artificial language, intended to be universal, devised by Dr. Zamenhof, a Russian, who adopted the pseudonym "Dr. Esperanto" in publishing his first pamphlet regarding it in 1887. The vocabulary is very largely based upon words common to the chief European languages, and sounds peculiar to any one language are eliminated. The spelling is phonetic, and the accent (stress) is always on the penult. A revised and simplified form, called Ido was developed in 1907, but Esperanto remained at the end of the 20th century the most popular aritficial language designed for normal human linguistic communication.

the common language spoken by most Riverdwellers; spread to the masses by the Church of the Second Chance

an artificial language based as far as possible on words common to all the European languages

A fake language which nobody speaks. One of the strips (#435, "Socian Komentaron") was translated into Esperanto for laughs. Most crucial to this process was the choice of the word proper translation of the word spurt.

The name derives from Doktoro Esperanto, the pseudonym under which L. L. Zamenhof first published the Unua Libro in 1887. The word itself means 'one who hopes'.