Esperanto is the world's most widely spoken constructed international auxiliary language. Created by L. L. Zamenhof in 1887, it is intended to be a universal second language for international communication, or "the international language". Zamenhof first described the language in Dr. Esperanto's International Language, which he published under the pseudonym Doktoro Esperanto. Early adopters of the language liked the name Esperanto and soon used it to describe his language. The word esperanto translates into English as "one who hopes".
7th Esperanto congress, Antwerp, August 1911
The Republic of Rose Island used Esperanto as its official language in 1968
Esperanto books at the World Esperanto Congress, Rotterdam 2008
Hungarian Cosmonaut Bertalan Farkas, the first Esperantist in space
A constructed language is a language whose phonology, grammar, and vocabulary, instead of having developed naturally, are consciously devised for some purpose, which may include being devised for a work of fiction. A constructed language may also be referred to as an artificial, planned or invented language, or a fictional language. Planned languages are languages that have been purposefully designed; they are the result of deliberate, controlling intervention and are thus of a form of language planning.
Page 68r of the Voynich manuscript. This three-page foldout from the manuscript includes a chart that appears astronomical.