Comprehensive language code information, consisting of ISO 639-1, ISO 639-2 and IETF language types.
Data is taken from the Library of Congress as the ISO 639-2 Registration Authority, and from the Unicode Common Locale Data Repository.
This file contains the 184 languages with ISO 639-1 (alpha 2 / two letter) codes and their English names.
This file contains the 184 languages with both ISO 639-2 (alpha 3 / three letter) bibliographic codes and ISO 639-1 codes, and their English names.
This file is more exhaustive.
It contains all languages with ISO 639-2 (alpha 3 / three letter) codes, the respective ISO 639-1 codes (if present), as well as the English and French name of each language.
There are two versions of the three letter codes: bibliographic and terminologic. Each language has a bibliographic code but only a few languages have terminologic codes. Terminologic codes are chosen to be similar to the corresponding ISO 639-1 two letter codes.
Example from Wikipedia:
[...] the German language (Part 1:
de) has two codes in Part 2:ger(T code) anddeu(B code), whereas there is only one code in Part 2,eng, for the English language.
There are four special codes: mul, und, mis, zxx; and a reserved range qaa-qtz.
This file lists all IETF language tags of the official resource indicated by http://www.iana.org/assignments/language-tag-extensions-registry
that into the /main folder of http://www.unicode.org/Public/cldr/latest/core.zip (project cldr.unicode.org).
This dataset is automatically updated using Github Workflows using scripts to gather ietf-language-tags.csv and different language-codes data.
This material is licensed by its maintainers under the Public Domain Dedication and License (PDDL).
Nevertheless, it should be noted that this material is ultimately sourced from the Library of Congress as a Registration Authority for ISO and their licensing policies are somewhat unclear. As this is a short, simple database of facts, there is a strong argument that no rights can subsist in this collection.
However, if you intended to use these data in a public or commercial product, please check the original sources for any specific restrictions.