An international auxiliary language (sometimes abbreviated as IAL or auxlang) is a language used (or to be used in the future) for communication between people from different nations who do not share a common native language. Although proposals have been made for existing languages to serve as an official international auxiliary language, the concept has been most commonly associated with constructed languages such as Esperanto which were designed from the beginning to serve this purpose. See also lingua franca.
The term "auxiliary" implies that it is intended to be an additional language for the people of the world, rather than replace their native languages. Often, the phrase is used to refer to constructed languages proposed specifically to ease worldwide international communication, such as Esperanto, Ido, Interlingua, Volapük, Glosa, Folkspraak, Mondlango, Lingua Franca Nova and others. However, it can also refer to the concept of such a language being determined by international consensus, including even a natural language so chosen.
Invented auxiliary languages are not widely used; nor have natural languages such as English and French penetrated universally, as some people imagine. Moreover, advocates of various languages disagree about which language should be universal. To overcome these difficulties, it has been proposed that some language (natural or invented) be chosen by consensus of officials elected by the nations of the world, in consultation with experts of various disciplines, a top_down approach. There would be a spoken and a written form. The language would be implemented in each nation as an additional (second) language, alongside the national languages. A bottom-up strategy tries to spread the language among ordinary users, so that it becomes the de facto standard.
The adoption of an official script for the blind has also been proposed, to correspond to the chosen written international language. Moreover, sign languages like Gestuno have been proposed as a lingua franca for the deaf, since there are various mutually unintelligible sign languages. Some believe that such a sign language need not correspond to the spoken or written forms of the chosen international language because sign languages are independent of those forms.
However, as with Esperanto and similar languages, the idea has not yet spread as widely as intended. Some people see the need for an official political endorsement from the nations of the world, backed by resources for instruction and implementation.
OneTongue.com (http://onetongue.com) - A website dedicated to spreading the idea of a world auxiliary language by a word-of-mouth or "word-by-email" campaign.
The Function of an International Auxiliary Language (http://www.geocities.com/Athens/Forum/5037/sapir.html) - An article written by linguist Edward Sapir discussing the need for prospects of an international language.
Conlang Directory: International Communication (http://www.langmaker.com/db/condir_internationalcommunication.htm) - A page of links to over 170 auxlangs.