Interlinguistics, also known as cosmoglottics, is the science of planned languages that has existed for more than a century. Formalised by Otto Jespersen in 1931 as the science of interlanguages, in more recent times, the field has been more focused with language planning, the collection of strategies to deliberately influence the structure and function of a living language. In this framework, interlanguages become a subset of planned languages, i.e. extreme cases of language planning.
Interlinguistics first appeared as a branch of studies devoted to the establishment of norms for auxiliary languages, but over its century-long history it has been understood by different authors more and more broadly as an interdisciplinary branch of science which includes various aspects of communication, language planning and standardization, multilingualism and globalisation, language policy, translation, sociolinguistics, intercultural communication, the history of language creation and literature written in constructed languages (international auxiliary languages (auxlangs) as well as constructed languages : conlangs), fictional artistic languages (artlangs), lingua francas, pidgins, creoles and constructed languages in the internet and other topics were added.
