IDL

Interactive Data Language (IDL) is a proprietary programming language for data science maintained by Exelis Visual Information Solutions, Inc., a subsidiary of the Harris Corporation.

Little information on the Web is available on the origins of this language. (This author could not find reliable sources to corroborate the history section on Wikipedia, including the alleged release date of 1977.) It is poorly documented and, according to one blogger, made some "interesting" design choices.