Words lists
All words in all languages:
https://github.com/eymenefealtun/all-words-in-all-languages
Words by frequency:
https://github.com/oprogramador/most-common-words-by-language
Google n-grams:
https://books.google.com/ngrams/info
Corpus from Beatuful Data
Lang iso codes:
https://en.wikipedia.org/wiki/List_of_ISO_639_language_codes