conlanger

keinokielen kehittäjä">keinokielen kehittäjä Someone who creates constructed languages (conlangs).
2005, Mari C. Jones, Ishtla Singh, Exploring Language Change, http://books.google.com.au/books?id=TbV7rglgk1YC&pg=PA154&dq=%22conlanger%22%7C%22conlangers%22&hl=en&sa=X&ei=lqYQUZnBK4HUkwXhyICABA&redir_esc=yv=onepage&q=%22conlanger%22%7C%22conlangers%22&f=false page 154,

The fact that the Internet has given visible shape to communities of invented language proponents through web sites and chat rooms for enthusiastic conlangers (‘language constructors’) has probably done little to dispel its reputation as a somewhat unusual and, to all intents and purposes, intangible undertaking.

The split was between two groups. The first was composed of people interested in quietly developing and discussing the languages they crafted for science-fictional worlds, what-if-a-language-did-this playfulness, or Tolkienesque fun (the true conlangers).

The goal of a conlanger, a language creator, is to realize a linguistic system that′s both unique and authentic—something that doesn't exist anywhere on Earth, but which a linguist wouldn′t be surprised to find in the wild.