1887 establishments in Poland

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".