ISO 639

The ISO standard ISO/FDIS 639-2, from the technical committee / subcommittee TC 37 / SC 2, contains references to 481 languages. Each reference is a three letters ID. Every position in the ID is from the a-z character set. No guarantees that the following list is up to date.
See www.loc.gov/standards/iso639-2/. This is not the ISO site, but the official list from ISO site is not free of charge.

Particular codes: art, mis, qaa-qtz

Language Name (English)
Nom de la langue (French)
ISO 639-1 ISO 639-2

ISO 639-1ISO 639-2Language Name (English)
Nom de la langue (French)