This is a more elaborate solution to the GuessBufferLanguage problem by BenjaminDrieu.

It works basically by counting occurrences of common words in every language that is known and comparing respective numbers. Languages currently supported are English, French, German, Danish, Polish, Spanish and somewhat Russian (based on loosely collected words from various .po files … does anybody want to help ?).

The file was posted to gnu.emacs.sources so you might have better luck there. See EmacsNewsgroups for the archive.

See also AutoLangMode.