diff --git a/lib/simpletest/todochecker.php b/lib/simpletest/todochecker.php
new file mode 100644
index 00000000000..093240a410c
--- /dev/null
+++ b/lib/simpletest/todochecker.php
@@ -0,0 +1,129 @@
+<?php
+
+// This file is part of Moodle - http://moodle.org/ 
+// 
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Check that, as in the coding guidelines, every to-do comment links to a tracker issue.
+ *
+ * As required by http://docs.moodle.org/en/Development:Coding_style.
+ *
+ * http://docs.moodle.org/en/Development:Coding_style
+ * @package   moodlecore
+ * @copyright 2009 Tim Hunt
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+require_once(dirname(__FILE__) . '/../../config.php');
+require_once($CFG->libdir . '/simpletestlib.php');
+
+require_login();
+$context = get_context_instance(CONTEXT_SYSTEM);
+require_capability('moodle/site:config', $context);
+
+$PAGE->set_url('lib/simpletest/todochecker.php');
+$PAGE->set_context($context);
+$PAGE->set_title('To-do checker');
+$PAGE->set_heading('To-do checker');
+
+$extensionstotest = array('php');
+$extensionsregex = '/\.(?:' . implode('|', $extensionstotest) . ')$/';
+$patterntofind = 'TO' . 'DO'; // Make it not match the regex.
+$found = array();
+
+echo $OUTPUT->header();
+echo $OUTPUT->heading('To-do checker', 2);
+
+echo $OUTPUT->box_start();
+echo 'Checking code ...';
+flush();
+recurseFolders($CFG->dirroot, 'check_to_dos', $extensionsregex);
+echo ' done.';
+echo $OUTPUT->box_end();
+
+if (empty($found)) {
+    echo '<p>No to-dos found.</p>';
+} else {
+    $total = 0;
+    foreach ($found as $filepath => $matches) {
+        $total += count($matches);
+    }
+
+    echo '<p>' . $total . ' to-dos found:</p><dl>';
+    foreach ($found as $filepath => $matches) {
+        echo '<dt>' . $filepath . ' <b>(' . count($matches) . ')</b></dt><dd><ul>';
+        foreach ($matches as $lineno => $line) {
+            $url = 'http://cvs.moodle.org/moodle/' . $filepath . '?view=annotate#l' . $lineno;
+            $error = '';
+
+            // Make sure there is a tracker issue id mentioned
+            $matches = array();
+            if (preg_match('/\bTODO\b.*?\b(MDL-\d+)/', $line, $matches)) {
+                $issueid = $matches[1];
+                $issueurl = 'http://tracker.moodle.org/browse/' . $issueid;
+
+                // Make sure the issue is still open.
+                if (issue_open($issueid)) {
+                    $issuename = $issueid;
+                } else {
+                    $issuename = '<strike>' . $issueid . '</strike>';
+                    $error = 'The associated tracker issue is Resolved.';
+                }
+
+                $line = str_replace($issueid, '<a href="' . $issueurl . '">' . $issuename . '</a>', htmlspecialchars($line));
+            } else {
+                $line = htmlspecialchars($line);
+                $error = 'No associated tracker issue.';
+            }
+
+            if ($error) {
+                $error = '<span class="error">' . $error . '</span>';
+            }
+            echo '<li><a href="' . $url . '">' . $lineno . '</a>: ' . $line . $error . '</li>';
+        }
+        echo '</ul></dd>';
+    }
+    echo '</dl>';
+}
+
+echo $OUTPUT->footer();
+
+function check_to_dos($filepath) {
+    global $CFG, $found;
+    $lines = file($filepath);
+    $matchesinfile = array();
+    foreach ($lines as $lineno => $line) {
+        if (preg_match('/\bTODO\b/', $line)) {
+            $matchesinfile[$lineno] = $line;
+        }
+    }
+    if (!empty($matchesinfile)) {
+        $shortpath = str_replace($CFG->dirroot . '/', '', $filepath);
+        $found[$shortpath] = $matchesinfile;
+    }
+}
+
+function issue_open($issueid) {
+    static $cache = array();
+    if (array_key_exists($issueid, $cache)) {
+        return $cache[$issueid];
+    }
+
+    $xmlurl = 'http://tracker.moodle.org/si/jira.issueviews:issue-xml/' . $issueid . '/' . $issueid . '.xml';
+    $content = download_file_content($xmlurl);
+    $result = preg_match('/Unresolved<\/resolution>/', $content);
+
+    $cache[$issueid] = $result;
+    return $result;
+}