You can get a list of available languages with `get_available_languages( $dir )`. It returns an array with all `.mo` files where the names does not start with `'continents-cities'`, `'ms-'` or `admin-`. To get a readable name for the file use `format_code_lang( $code )`. If you scan a directory for language files and get an array like `array( 'de_DE', 'tr_TR' )` this function will build translated names for the languages: `German` and `Turkish`.