Constructed languages introduced in the 1880s

Esperanto () is the world's most widely spoken constructed auxiliary language. Created by L. L. Zamenhof in 1887 as "the International Language" (), it is intended to be a universal second language for international communication. He described the language in ''Dr. Esperanto's International Language'' (known as , the "first book"), which he published under the pseudonym . Early adopters of the language liked the name and soon used it to describe his language. The word translates into English as "one who hopes".

Mundolinco is a constructed language created by the Dutch author J. Braakman in 1888. It is notable for apparently being the first Esperantido, i.e. the first Esperanto derivative, published the year after Esperanto was introduced in the Unua Libro.

thumb|The cover of the first edition of Pasilingua Pasilingua is an international auxiliary language proposed by Paul Steiner, first published in Neuwied in 1885 in his book Three World Language Systems (German: Drei Weltsprach-Systeme).