friendica/mod/opensearch.php

<?php
    function opensearch_content(App $a) {

		$tpl = get_markup_template('opensearch.tpl');

		header("Content-type: application/opensearchdescription+xml");

		$o = replace_macros($tpl, array(
			'$baseurl' => App::get_baseurl(),
			'$nodename' => $a->get_hostname(),
		));

		echo $o;

		killme();

	}
?>