In koala-framework is a trl.xml file where strings with source from Koala can be translated.

Strings with source application must be translated in a trl.xml in the application.

You can either edit the xml files manually, or use the trl controllers available in koala.

To use the controllers just add the following resources to your acl:

$this->add(new Kwf_Acl_Resource_MenuUrl('kwf_trl_web',
    array('text'=>trlKwf('Translation Web'), 'icon'=>'comment.png'),
    '/kwf/trl/web'), 'settings');
    $this->add(new Zend_Acl_Resource('kwf_trl_web-edit'), 'kwf_trl_web');
$this->add(new Kwf_Acl_Resource_MenuUrl('kwf_trl_kwf',
    array('text'=>trlKwf('Translation Common'), 'icon'=>'comment.png'),
    '/kwf/trl/kwf'), 'settings');
    $this->add(new Zend_Acl_Resource('kwf_trl_kwf-edit'), 'kwf_trl_kwf');

and the following dependency to your dependencies.ini:

Admin.dep[] = KwfTrlAdmin