load_theme_textdomain

# functions.php
<?php
// Load the Webeo_Core class
require_once TEMPLATEPATH . '/lib/webeo/Webeo_Core.class.php';

// Instantiate Webeo Themeframework
add_action('after_setup_theme', create_function('', 'return Webeo_Core::getInstance()->init();'), 9);
?>


# Webeo_Core.class.php
<?php
class Webeo_Core {

    // ...

    /**
     * Constructor for singleton pattern
     *
     * @return void
     */
    private function __construct() {

    }

    /**
     * Make clone private, so nobody can clone the instance
     *
     * @final
     * @return void
     */
    final private function __clone() {

    }

    /**
     * Get instance of Webeo_Core
     * Singleton pattern
     *
     * @static
     * @return Webeo_Core object
     */
    public static function getInstance() {
        if (is_null(self::$_instance)) {
            self::$_instance = new Webeo_Core();
        }

        return self::$_instance;
    }

    /**
     * Initialize the framework
     *
     * @return void
     */
    public function init() {
        if (self::$_initialized) {
            return;
        }

        // ...

        // FIXME
        // Set namespace for this theme and define path to language files
        $languages = ( is_dir( TEMPLATEPATH . '/languages' ) ) ? TEMPLATEPATH . '/languages' : TEMPLATEPATH;
        load_theme_textdomain('webeo', $languages);

        // ...

        self::$_initialized = true;
    }
}
?>