admin/environment/php extension/simplexml
From MoodleDocs
Note: You are currently viewing documentation for Moodle 3.3. Up-to-date documentation for the latest stable version of Moodle is probably available here: admin/environment/php extension/simplexml.
This article is a stub. Please help improve Moodle Docs by editing it and adding some content.
Please see http://php.net/manual/en/book.simplexml.php