Magento – “Interface Locale” admin language problem

Here is possible solution. Not the most elegant but it should work.
First you should get all the languages that appear in the backend in the locale config section.

$allLanguages = Mage::app()->getLocale()->getOptionLocales();

This will get you an array like this:

Array
(
    [0] => Array
        (
            [value] => af_ZA
            [label] => Afrikaans (South Africa)
        )

    [1] => Array
        (
            [value] => sq_AL
            [label] => Albanian (Albania)
        )

    ...
)

You can get the current locale code like you already do

$localeCode = Mage::getStoreConfig('general/locale/code', $_lang->getId());

Now all you have to do is to loop through all the languages and see if one matches your code.

$languageLabel = '';
foreach ($allLanguages as $language) {
    if ($language['value'] == $localeCode) {
        $languageLabel = $language['label'];
        break;
    }
}

If you want to lose the country name just do this.

$parts = explode('(', $languageLabel);
$languageLabel = trim($parts[0]);

Or you can use a regex that seams cleaner.

Of course you should wrap all this code in a method and just use that method.

[EDIT]
An other approach would be to get all the languages based on the language code only:

$languages = Zend_Locale::getTranslationList('language', Mage::app()->getLocale()->getLocaleCode());//replace with own locale.

this should return something like

[en] -> English
[fr] -> French

Then you have to get the lang code like this (you already do that):

$_languageCode = substr(Mage::getStoreConfig('general/locale/code', $_lang->getId()),0,2);

And just check

`if (isset($languages[$langCode]))`  

This seams cleaner but I'm not sure if it works correctly for all the values.
The first method seams safer because it uses the same options that you see in the backend.
Give either one of them a try.

[EDIT] Example of the final code from the question author (works like a charm)

    <!-- LANGUAGES BOF -->
<?php if(count($this->getStores())>1): ?>
<?php
$stores = array();
$_current = null;

$languages = Zend_Locale::getTranslationList('language', Mage::app()->getLocale()->getLocaleCode());

foreach ($this->getStores() as $_lang) {

    $_selected = $_selected_option = $_language_name = '';
    $_language_code = substr(Mage::getStoreConfig('general/locale/code', $_lang->getId()),0,2);
    if (isset($languages[$_language_code])) {$_language_name = $languages[$_language_code];} 
    $parts = explode('(', $_language_name);
    $_language_name = trim($parts[0]);

    if ( ($_lang->getId() == $this->getCurrentStoreId()) ) {
     $_current =  $_lang;
     $_current_lang = $_language_name;
     $_selected = ' class="selected"';
     $_selected_option = ' selected="selected"';
    }

    // $stores[] = '<li'. $_selected .'><a style="background-image:url(\''. $this->getSkinUrl('images/flags/'.$_lang->getCode().'.png') .'\');" href="'. $_lang->getCurrentUrl() .'">'. $this->htmlEscape($_lang->getName()) .'</a></li>';
    $stores[] = '<li'. $_selected .'><a style="background-image:url(\''. $this->getSkinUrl('images/flags/'.$_language_code.'.png') .'\');" href="'. $_lang->getCurrentUrl() .'">'. $this->htmlEscape($_language_name) .'</a></li>';
    $select_stores[] = '<option '.$_selected_option.' value="'. $_lang->getCurrentUrl() .'">'. $this->htmlEscape($_lang->getName()) .'</option>';
}

?>
<div class="header-switch language-switch">
    <span><?php echo $this->__('Your Language:') ?>
        <span class="current"><?php echo $this->htmlEscape($_current_lang); ?></span>
    </span>
    <div class="header-dropdown">
        <ul><?php echo implode('', $stores); ?></ul>
    </div>
</div>

Here is the solution

https://github.com/jreinke/magento-hide-default-store-code

Remove this format: ?___store=english for english and ?___store=arabic

In the design file find the languages.phtml

/app/design/frontend/default/template/page/switch/languages.phtml

In the line 41

echo $_lang->getCurrentUrl()

Add 'false' as parameter

echo $_lang->getCurrentUrl(false)

Actual Url:

http:example.com?___store=english for english and ?___store=arabic

After added the false parameter in $_lang->getCurrentUrl(false) method. Url will be generated like the below

http:example.com?___store=english