Template:Language name/en
This template was generated by taking the list of Valve Developer Community's languages from its API, and cross referencing it with MediaWiki's more up to date API to match each language with a BCP-47 tag. IANA's assignments of region + language codes and ISO 15924's assignments of codes for writing systems were then used to give each tag a name in English.
IANA's redundant assignments were used to categorize variants of Chinese. The descriptors "Traditional" or "Simplified" were removed from national variants.
zh-my is simply "Malaysian Chinese" because the standard does not give it a redundant tag like zh-hk, so it must be parsed as a language name and country, similar to en-ca
Akan was added manually, because MediaWiki's API did not mention it, likely due to it being split into several languages.
de-ch was changed from "Swiss German" to "Swiss High German" (the literal translation of {{#language:de-ch}}) to differentiate it from als and gsw, which are for Swiss German, the dialect of Alemannic.
Other small edits were made to language names, such as removing the date range from Old English.