L. L. Zamenhof, Polish linguist and ophthalmologist, created Esperanto (died 1917)

L. L. Zamenhof was the creator of Esperanto, the most widely used constructed international auxiliary language.

Esperanto is the world's most widely spoken constructed international auxiliary language. Created by L. L. Zamenhof in 1887 to be '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, 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 translates into English as 'one who hopes'.

December 15 is the 349th day of the year in the Gregorian calendar; 16 days remain until the end of the year.