I have used languages.js (from Kiwix core) to improve www.kiwix.org mobile backend at http://www.kiwix.org/m/. Although this file was improved recently to support all ISO languages, its database is obviously not complete. Many language are not supported and have still their ISO code in the language selectbox.
I think that its done
This version of the software is deprecated. New version Kiwix Desktop 2.0 should be used.