Use Gettext to translate Magento modules

Narno_Gettext_Model_Translate.php

<?php
/**
 * Narno Gettext Translate model
 * (overlap of Mage_Core_Model_Translate)
 *
 * Support Gettext file (binary).
 */
class Narno_Gettext_Model_Translate extends Mage_Core_Model_Translate
{
    [...]
    /**
     * Config file: translate files types
     */
    const TYPE_DEFAULT = 'csv'; // xml path: translate/modules/{My_Module}/files/default
    const TYPE_CSV     = 'csv'; // xml path: translate/modules/{My_Module}/files/csv
    const TYPE_MO      = 'mo';  // xml path: translate/modules/{My_Module}/files/mo
    [...]

    [...]
    /**
     * Loading data from module translation files
     *
     * @param   string $moduleName
     * @param   string $files
     * @return  Mage_Core_Model_Translate
     */
    protected function _loadModuleTranslation($moduleName, $files, $forceReload=false)
    {
        foreach ($files as $type=>$file) {
            $file = $this->_getModuleFilePath($moduleName, $file);
            $this->_addData($this->_getFileData($file, $type), $moduleName, $forceReload);
        }
        return $this;
    }
    [...]

    [...]
    /**
     * Retrieve data from file
     *
     * @param   string $file
     * @param   string $type ("default", "csv" or "mo")
     * @return  array
     */
    protected function _getFileData($file, $type)
    {
        $data = array();
        if (file_exists($file)) {
            switch ($type) {
                case self::TYPE_MO:
                    $getText = new Zend_Translate_Adapter_Gettext($file, $this->getLocale());
                    $data = $getText->getMessages();
                    break;
                case self::TYPE_CSV:
                case self::TYPE_DEFAULT:
                default:
                    $parser = new Varien_File_Csv();
                    $parser->setDelimiter(self::CSV_SEPARATOR);
                    $data = $parser->getDataPairs($file);
                    break;
            }
        }
        return $data;
    }
    [...]
}

Narno_Gettext_Model_Translate_Example_of_using.xml

<config>
    <frontend>
        <translate>
            <modules>
                <{My_Module}>
                    <files>
                        <mo>{My_Module}.mo</mo>
                    </files>
                </{My_Module}>
            </modules>
        </translate>
    </frontend>
</config>