This file lists the codes for each country provided in ISO 3166. There are two tables: existing codes and withdrawn codes.

The Library of Congress has been designated the ISO 639-2/RA for the purpose of processing requests for alpha-3 language codes comprising the International Standard, Codes for the representation of names of languages-- Part 2: alpha-3 code.

Oh yes, iso-3166 and iso-639 are so obvious standards, one might think. This I thought when I tried to compile a comprehensive table for PApp. However, the actual situation is more complex: There are different versions of each standard containing different data sets that make it impossible to compile a comprehensive table that contains all the information.