It can be done by writing your own implemented Zend_View_Interface, but I wonder why this would be necessary?

Or you could extend the Zend_View class to include smarty. Another factor is you can chain parse the templates as I would assume you aren't passing the same data to both template engines?

$view->data = test;
$smarty->name = someName;
$view->render($smarty->render(index.tpl));

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Zym Framework - A Zend Framework extension library w/ demo app

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