International auxiliary language

An International auxiliary language (shortly IAL or auxlang) is a language that is intended for communication between people who have different first languages.
Languages of large societies over the centuries have almost reached the international level, for example Latin, Greek, Standard Arabic, Standard Chinese, English, French, Portuguese, Russian, and Spanish.
Some people have turned to the idea of promoting an artificial or constructed language as a possible IAL, for example Esperanto, Ido and Interlingua.