Auxlang

One of the most successful auxlangs is Esperanto, which has native speakers.

A distinction is usually made between auxiliary languages (auxlangs), designed with international communication as a deliberate goal, and “conlangs,” usually constructed for other purposes. (The Elvish languages showcased by Tolkien[…]and the Klingon language[…]are conlangs rather than auxlangs.)

Volapük was the first auxlang to develop a community of speakers, after its launch in 1879 by Schleyer (Eco, 1993).

Since at least the 17th century (and quite probably before that), various people have created artificially constructed languages (or conlangs), for the most part in order to offer humanity a neutral, easily mastered and logical means of interethnic communication (an auxlang)

The second was composed of those who wanted to talk about an international auxiliary language for the real world (the auxlangers). The auxlang group included a few devoted Esperantists and a larger group[…].