The following code is a wrapper to support calls to some of the old xslt_* functions:
<?
if (PHP_VERSION >= 5) {
    function xslt_create() {
        return new XsltProcessor();
    }
    function xslt_process($xsltproc, 
                          $xml_arg, 
                          $xsl_arg, 
                          $xslcontainer = null, 
                          $args = null, 
                          $params = null) {
        $xml_arg = str_replace('arg:', '', $xml_arg);
        $xsl_arg = str_replace('arg:', '', $xsl_arg);
        $xml = new DomDocument;
        $xsl = new DomDocument;
        $xml->loadXML($args[$xml_arg]);
        $xsl->loadXML($args[$xsl_arg]);
        $xsltproc->importStyleSheet($xsl);
        if ($params) {
            foreach ($params as $param => $value) {
                $xsltproc->setParameter("", $param, $value);
            }
        }
        $processed = $xsltproc->transformToXML($xml);
        if ($xslcontainer) {
            return @file_put_contents($xslcontainer, $processed);
        } else {
            return $processed;
        }
    }
    function xslt_free($xsltproc) {
        unset($xsltproc);
    }
}
$arguments = array(
    '/_xml' => file_get_contents("newxslt.xml"),
    '/_xsl' => file_get_contents("newxslt.xslt")
);
$xsltproc = xslt_create();
$html = xslt_process(
    $xsltproc, 
    'arg:/_xml', 
    'arg:/_xsl', 
    null, 
    $arguments
);
xslt_free($xsltproc);
print $html;
?>