diff --git a/admin/auth.php b/admin/auth.php
index c5ebb80b758..934acd371ef 100644
--- a/admin/auth.php
+++ b/admin/auth.php
@@ -12,7 +12,7 @@ require_once($CFG->libdir.'/adminlib.php');
 require_once($CFG->libdir.'/tablelib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 $returnurl = new moodle_url('/admin/settings.php', array('section'=>'manageauths'));
 
diff --git a/admin/category.php b/admin/category.php
index f9cd940e9ff..1d68207221c 100644
--- a/admin/category.php
+++ b/admin/category.php
@@ -32,7 +32,7 @@ $adminediting = optional_param('adminedit', -1, PARAM_BOOL);
 
 /// no guest autologin
 require_login(0, false);
-$PAGE->set_context(get_context_instance(CONTEXT_SYSTEM));
+$PAGE->set_context(context_system::instance());
 $PAGE->set_url('/admin/category.php', array('category' => $category));
 $PAGE->set_pagetype('admin-setting-' . $category);
 $PAGE->set_pagelayout('admin');
diff --git a/admin/editors.php b/admin/editors.php
index 743d083e43b..1a8f530854a 100644
--- a/admin/editors.php
+++ b/admin/editors.php
@@ -9,7 +9,7 @@ require_once($CFG->libdir.'/adminlib.php');
 require_once($CFG->libdir.'/tablelib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 $returnurl = "$CFG->wwwroot/$CFG->admin/settings.php?section=manageeditors";
 
diff --git a/admin/enrol.php b/admin/enrol.php
index dee82d3c559..9fc196f54c0 100644
--- a/admin/enrol.php
+++ b/admin/enrol.php
@@ -34,7 +34,7 @@ $PAGE->set_url('/admin/enrol.php');
 $PAGE->set_context(context_system::instance());
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 require_sesskey();
 
 $enabled = enrol_get_plugins(true);
diff --git a/admin/filters.php b/admin/filters.php
index 8af8da06609..5c65c74085c 100644
--- a/admin/filters.php
+++ b/admin/filters.php
@@ -38,7 +38,7 @@
     $filterpath = optional_param('filterpath', '', PARAM_PATH);
 
     require_login();
-    $systemcontext = get_context_instance(CONTEXT_SYSTEM);
+    $systemcontext = context_system::instance();
     require_capability('moodle/site:config', $systemcontext);
 
     $returnurl = "$CFG->wwwroot/$CFG->admin/filters.php";
diff --git a/admin/handlevirus.php b/admin/handlevirus.php
index 9e32cc0b653..d7cf3cd9900 100644
--- a/admin/handlevirus.php
+++ b/admin/handlevirus.php
@@ -49,7 +49,7 @@ while(!feof($fd)) {
     $a->date = userdate($log->time);
 
     $a->action = $action;
-    $a->course = format_string($course->fullname, true, array('context' => get_context_instance(CONTEXT_COURSE, $course->id)));
+    $a->course = format_string($course->fullname, true, array('context' => context_course::instance($course->id)));
     $a->user = fullname($user);
 
     notify_user($user,$subject,$a);
diff --git a/admin/index.php b/admin/index.php
index ffc923cff5c..410cbf6723b 100644
--- a/admin/index.php
+++ b/admin/index.php
@@ -185,7 +185,7 @@ if (!core_tables_exist()) {
 // and upgrade if possible.
 
 $stradministration = get_string('administration');
-$PAGE->set_context(get_context_instance(CONTEXT_SYSTEM));
+$PAGE->set_context(context_system::instance());
 
 if (empty($CFG->version)) {
     print_error('missingconfigversion', 'debug');
@@ -378,7 +378,7 @@ if (during_initial_install()) {
 
 // Check for valid admin user - no guest autologin
 require_login(0, false);
-$context = get_context_instance(CONTEXT_SYSTEM);
+$context = context_system::instance();
 require_capability('moodle/site:config', $context);
 
 // check that site is properly customized
diff --git a/admin/licenses.php b/admin/licenses.php
index 517ba85291d..47d3929201c 100644
--- a/admin/licenses.php
+++ b/admin/licenses.php
@@ -24,7 +24,7 @@ require_once($CFG->libdir.'/adminlib.php');
 require_once($CFG->libdir.'/licenselib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 $returnurl = "$CFG->wwwroot/$CFG->admin/settings.php?section=managelicenses";
 
diff --git a/admin/message.php b/admin/message.php
index 45d9026c14e..88e8f856617 100644
--- a/admin/message.php
+++ b/admin/message.php
@@ -29,7 +29,7 @@ require_once($CFG->libdir.'/adminlib.php');
 admin_externalpage_setup('managemessageoutputs');
 
 // Require site configuration capability
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 // Get the submitted params
 $disable    = optional_param('disable', 0, PARAM_INT);
@@ -82,7 +82,7 @@ if ($disable || $enable || $uninstall) {
     redirect($url);
 }
 // Page settings
-$PAGE->set_context(get_context_instance(CONTEXT_SYSTEM));
+$PAGE->set_context(context_system::instance());
 
 // Grab the renderer
 $renderer = $PAGE->get_renderer('core', 'message');
diff --git a/admin/mnet/access_control.php b/admin/mnet/access_control.php
index b9e436f7cc4..0354f150ac6 100644
--- a/admin/mnet/access_control.php
+++ b/admin/mnet/access_control.php
@@ -22,7 +22,7 @@ if (!extension_loaded('openssl')) {
     print_error('requiresopenssl', 'mnet');
 }
 
-$sitecontext = get_context_instance(CONTEXT_SYSTEM);
+$sitecontext = context_system::instance();
 $sesskey = sesskey();
 $formerror = array();
 
diff --git a/admin/mnet/delete.php b/admin/mnet/delete.php
index e3a7e3f07fb..c078b274c30 100644
--- a/admin/mnet/delete.php
+++ b/admin/mnet/delete.php
@@ -36,7 +36,7 @@ $hostid = required_param('hostid', PARAM_INT);
 
 require_login();
 
-$context = get_context_instance(CONTEXT_SYSTEM);
+$context = context_system::instance();
 require_capability('moodle/site:config', $context, $USER->id, true, "nopermissions");
 
 $mnet = get_mnet_environment();
diff --git a/admin/mnet/index.php b/admin/mnet/index.php
index 54a0a276a5a..d81e8a92ad6 100644
--- a/admin/mnet/index.php
+++ b/admin/mnet/index.php
@@ -9,7 +9,7 @@
     require_login();
     admin_externalpage_setup('net');
 
-    $context = get_context_instance(CONTEXT_SYSTEM);
+    $context = context_system::instance();
 
     require_capability('moodle/site:config', $context, $USER->id, true, "nopermissions");
 
diff --git a/admin/mnet/peers.php b/admin/mnet/peers.php
index e7c1daf821b..40759dbc0ed 100644
--- a/admin/mnet/peers.php
+++ b/admin/mnet/peers.php
@@ -34,7 +34,7 @@ require_once($CFG->dirroot.'/'.$CFG->admin.'/mnet/peer_forms.php');
 
 require_login();
 
-$context = get_context_instance(CONTEXT_SYSTEM);
+$context = context_system::instance();
 require_capability('moodle/site:config', $context, $USER->id, true, 'nopermissions');
 
 /// Initialize variables.
diff --git a/admin/mnet/profilefields.php b/admin/mnet/profilefields.php
index 23443e90636..5f5fd6b1ec0 100644
--- a/admin/mnet/profilefields.php
+++ b/admin/mnet/profilefields.php
@@ -34,7 +34,7 @@ $hostid = required_param('hostid', PARAM_INT);
 $mnet_peer = new mnet_peer();
 $mnet_peer->set_id($hostid);
 
-$context = get_context_instance(CONTEXT_SYSTEM);
+$context = context_system::instance();
 
 require_capability('moodle/site:config', $context, $USER->id, true, 'nopermissions');
 admin_externalpage_setup('mnetpeers');
diff --git a/admin/mnet/services.php b/admin/mnet/services.php
index d496f47a6e6..cdc4fe3a5c2 100644
--- a/admin/mnet/services.php
+++ b/admin/mnet/services.php
@@ -33,7 +33,7 @@ $mnet = get_mnet_environment();
 require_login();
 admin_externalpage_setup('mnetpeers');
 
-$context = get_context_instance(CONTEXT_SYSTEM);
+$context = context_system::instance();
 require_capability('moodle/site:config', $context, $USER->id, true, "nopermissions");
 
 $hostid = required_param('hostid', PARAM_INT);
diff --git a/admin/mnet/testclient.php b/admin/mnet/testclient.php
index f4d2c96053a..89734e39b14 100644
--- a/admin/mnet/testclient.php
+++ b/admin/mnet/testclient.php
@@ -24,7 +24,7 @@ if ($CFG->mnet_dispatcher_mode === 'off') {
 require_login();
 admin_externalpage_setup('mnettestclient');
 
-$context = get_context_instance(CONTEXT_SYSTEM);
+$context = context_system::instance();
 require_capability('moodle/site:config', $context);
 
 error_reporting(DEBUG_ALL);
diff --git a/admin/mnet/trustedhosts.php b/admin/mnet/trustedhosts.php
index 8f0bef15fdf..290c0ae9212 100644
--- a/admin/mnet/trustedhosts.php
+++ b/admin/mnet/trustedhosts.php
@@ -8,7 +8,7 @@
     require_login();
     admin_externalpage_setup('trustedhosts');
 
-    $context = get_context_instance(CONTEXT_SYSTEM);
+    $context = context_system::instance();
 
     require_capability('moodle/site:config', $context, $USER->id, true, "nopermissions");
 
diff --git a/admin/oacleanup.php b/admin/oacleanup.php
index 891a20af947..fe2e444472b 100644
--- a/admin/oacleanup.php
+++ b/admin/oacleanup.php
@@ -49,7 +49,7 @@ function online_assignment_cleanup($output=false) {
     /// cycle through each course
     foreach ($courses as $course) {
         context_instance_preload($course);
-        $context = get_context_instance(CONTEXT_COURSE, $course->id);
+        $context = context_course::instance($course->id);
 
         if (empty($course->fullname)) {
             $fullname = get_string('course').': '.$course->id;
diff --git a/admin/plugins.php b/admin/plugins.php
index 943f23a5ea8..8da3fd7a5fe 100644
--- a/admin/plugins.php
+++ b/admin/plugins.php
@@ -28,7 +28,7 @@ require_once(dirname(dirname(__FILE__)) . '/config.php');
 require_once($CFG->libdir . '/adminlib.php');
 require_once($CFG->libdir . '/pluginlib.php');
 
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 admin_externalpage_setup('pluginsoverview');
 
 $fetchremote = optional_param('fetchremote', false, PARAM_BOOL);
diff --git a/admin/portfolio.php b/admin/portfolio.php
index 09a769577c3..77aa8ea13a7 100644
--- a/admin/portfolio.php
+++ b/admin/portfolio.php
@@ -35,7 +35,7 @@ if ($action == 'newon') {
 
 admin_externalpage_setup($pagename);
 
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 $baseurl    = "$CFG->wwwroot/$CFG->admin/portfolio.php";
 $sesskeyurl = "$CFG->wwwroot/$CFG->admin/portfolio.php?sesskey=" . sesskey();
diff --git a/admin/purgecaches.php b/admin/purgecaches.php
index f437e8ac8a7..006bb0d9768 100644
--- a/admin/purgecaches.php
+++ b/admin/purgecaches.php
@@ -31,7 +31,7 @@ $confirm = optional_param('confirm', 0, PARAM_BOOL);
 admin_externalpage_setup('purgecaches');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 if ($confirm) {
     require_sesskey();
diff --git a/admin/qbehaviours.php b/admin/qbehaviours.php
index ce81b1369d2..1e72afad1aa 100644
--- a/admin/qbehaviours.php
+++ b/admin/qbehaviours.php
@@ -33,7 +33,7 @@ require_once($CFG->libdir . '/tablelib.php');
 
 // Check permissions.
 require_login();
-$systemcontext = get_context_instance(CONTEXT_SYSTEM);
+$systemcontext = context_system::instance();
 require_capability('moodle/question:config', $systemcontext);
 
 admin_externalpage_setup('manageqbehaviours');
diff --git a/admin/qtypes.php b/admin/qtypes.php
index cbe828fdf10..a37725cd837 100644
--- a/admin/qtypes.php
+++ b/admin/qtypes.php
@@ -33,7 +33,7 @@ require_once($CFG->libdir . '/tablelib.php');
 
 // Check permissions.
 require_login();
-$systemcontext = get_context_instance(CONTEXT_SYSTEM);
+$systemcontext = context_system::instance();
 require_capability('moodle/question:config', $systemcontext);
 $canviewreports = has_capability('report/questioninstances:view', $systemcontext);
 
diff --git a/admin/registration/forms.php b/admin/registration/forms.php
index 0126722d9f9..47a450f6126 100644
--- a/admin/registration/forms.php
+++ b/admin/registration/forms.php
@@ -203,7 +203,7 @@ class site_registration_form extends moodleform {
         $cleanhuburl = clean_param($huburl, PARAM_ALPHANUMEXT);
         $sitename = get_config('hub', 'site_name_' . $cleanhuburl);
         if ($sitename === false) {
-            $sitename = format_string($site->fullname, true, array('context' => get_context_instance(CONTEXT_COURSE, SITEID)));
+            $sitename = format_string($site->fullname, true, array('context' => context_course::instance(SITEID)));
         }
         $sitedescription = get_config('hub', 'site_description_' . $cleanhuburl);
         if ($sitedescription === false) {
diff --git a/admin/repository.php b/admin/repository.php
index 377a006fc67..0adfdc6e8e2 100644
--- a/admin/repository.php
+++ b/admin/repository.php
@@ -47,7 +47,7 @@ if ($action == 'newon') {
     $visible = false;
 }
 
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 admin_externalpage_setup($pagename);
 
 $sesskeyurl = $CFG->wwwroot.'/'.$CFG->admin.'/repository.php?sesskey=' . sesskey();
diff --git a/admin/roles/allow.php b/admin/roles/allow.php
index 45e9b038673..37ac157b5eb 100644
--- a/admin/roles/allow.php
+++ b/admin/roles/allow.php
@@ -41,7 +41,7 @@ if (!isset($classformode[$mode])) {
 $baseurl = new moodle_url('/admin/roles/allow.php', array('mode'=>$mode));
 admin_externalpage_setup('defineroles', '', array(), $baseurl);
 
-$syscontext = get_context_instance(CONTEXT_SYSTEM);
+$syscontext = context_system::instance();
 require_capability('moodle/role:manage', $syscontext);
 
 $controller = new $classformode[$mode]();
diff --git a/admin/roles/define.php b/admin/roles/define.php
index 60dbade27b0..d889a1065f0 100644
--- a/admin/roles/define.php
+++ b/admin/roles/define.php
@@ -56,7 +56,7 @@
     }
 
 /// Check access permissions.
-    $systemcontext = get_context_instance(CONTEXT_SYSTEM);
+    $systemcontext = context_system::instance();
     require_login();
     require_capability('moodle/role:manage', $systemcontext);
     admin_externalpage_setup('defineroles', '', array('action' => $action, 'roleid' => $roleid), $defineurl);
diff --git a/admin/roles/lib.php b/admin/roles/lib.php
index 490e0a133c8..11341d10cfe 100644
--- a/admin/roles/lib.php
+++ b/admin/roles/lib.php
@@ -1270,7 +1270,7 @@ abstract class role_allow_role_page {
      */
     protected function load_required_roles() {
     /// Get all roles
-        $this->roles = role_fix_names(get_all_roles(), get_context_instance(CONTEXT_SYSTEM), ROLENAME_ORIGINAL);
+        $this->roles = role_fix_names(get_all_roles(), context_system::instance(), ROLENAME_ORIGINAL);
     }
 
     /**
diff --git a/admin/roles/manage.php b/admin/roles/manage.php
index 85b1c0b240b..745681ee268 100644
--- a/admin/roles/manage.php
+++ b/admin/roles/manage.php
@@ -47,7 +47,7 @@
     $defineurl = $CFG->wwwroot . '/' . $CFG->admin . '/roles/define.php';
 
 /// Check access permissions.
-    $systemcontext = get_context_instance(CONTEXT_SYSTEM);
+    $systemcontext = context_system::instance();
     require_login();
     require_capability('moodle/role:manage', $systemcontext);
     admin_externalpage_setup('defineroles');
diff --git a/admin/roles/usersroles.php b/admin/roles/usersroles.php
index 11b2c28caf9..d9d8cb5e8f7 100644
--- a/admin/roles/usersroles.php
+++ b/admin/roles/usersroles.php
@@ -36,9 +36,9 @@ $courseid = required_param('courseid', PARAM_INT);
 $user = $DB->get_record('user', array('id' => $userid), '*', MUST_EXIST);
 $course = $DB->get_record('course', array('id' => $courseid), '*', MUST_EXIST);
 
-$usercontext = get_context_instance(CONTEXT_USER, $user->id);
-$coursecontext = get_context_instance(CONTEXT_COURSE, $course->id);
-$systemcontext = get_context_instance(CONTEXT_SYSTEM);
+$usercontext = context_user::instance($user->id);
+$coursecontext = context_course::instance($course->id);
+$systemcontext = context_system::instance();
 
 $baseurl = new moodle_url('/admin/roles/usersroles.php', array('userid'=>$userid, 'courseid'=>$courseid));
 
diff --git a/admin/search.php b/admin/search.php
index 40fbeb4b56d..d60f09374d1 100644
--- a/admin/search.php
+++ b/admin/search.php
@@ -7,7 +7,7 @@ require_once($CFG->libdir.'/adminlib.php');
 
 $query = trim(optional_param('query', '', PARAM_NOTAGS));  // Search string
 
-$PAGE->set_context(get_context_instance(CONTEXT_SYSTEM));
+$PAGE->set_context(context_system::instance());
 
 admin_externalpage_setup('search', '', array('query' => $query)); // now hidden page
 
diff --git a/admin/settings.php b/admin/settings.php
index 3e66f24d48e..c8444c51bf1 100644
--- a/admin/settings.php
+++ b/admin/settings.php
@@ -9,7 +9,7 @@ $adminediting = optional_param('adminedit', -1, PARAM_BOOL);
 
 /// no guest autologin
 require_login(0, false);
-$PAGE->set_context(get_context_instance(CONTEXT_SYSTEM));
+$PAGE->set_context(context_system::instance());
 $PAGE->set_url('/admin/settings.php', array('section' => $section));
 $PAGE->set_pagetype('admin-setting-' . $section);
 $PAGE->set_pagelayout('admin');
diff --git a/admin/settings/frontpage.php b/admin/settings/frontpage.php
index fd5fafa6f32..5a060a101bb 100644
--- a/admin/settings/frontpage.php
+++ b/admin/settings/frontpage.php
@@ -3,7 +3,7 @@
 // This file defines everything related to frontpage
 
 if (!during_initial_install()) { //do not use during installation
-    $frontpagecontext = get_context_instance(CONTEXT_COURSE, SITEID);
+    $frontpagecontext = context_course::instance(SITEID);
 
     if ($hassiteconfig or has_any_capability(array(
             'moodle/course:update',
diff --git a/admin/settings/top.php b/admin/settings/top.php
index 147a4e56edd..cd52953d029 100644
--- a/admin/settings/top.php
+++ b/admin/settings/top.php
@@ -5,7 +5,7 @@
 // since they need to exist *before* settingpages and externalpages
 // are added to them.
 
-$systemcontext = get_context_instance(CONTEXT_SYSTEM);
+$systemcontext = context_system::instance();
 $hassiteconfig = has_capability('moodle/site:config', $systemcontext);
 
 $ADMIN->add('root', new admin_externalpage('adminnotifications', new lang_string('notifications'), "$CFG->wwwroot/$CFG->admin/index.php"));
diff --git a/admin/settings/users.php b/admin/settings/users.php
index fa5968c5474..b7f1e257947 100644
--- a/admin/settings/users.php
+++ b/admin/settings/users.php
@@ -34,7 +34,7 @@ if ($hassiteconfig
     $temp = new admin_settingpage('userpolicies', new lang_string('userpolicies', 'admin'));
     if ($ADMIN->fulltree) {
         if (!during_initial_install()) {
-            $context = get_context_instance(CONTEXT_SYSTEM);
+            $context = context_system::instance();
 
             $otherroles      = array();
             $guestroles      = array();
diff --git a/admin/timezone.php b/admin/timezone.php
index e031be44bbe..8cfefc7b7a4 100644
--- a/admin/timezone.php
+++ b/admin/timezone.php
@@ -14,7 +14,7 @@
 
     require_login();
 
-    require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+    require_capability('moodle/site:config', context_system::instance());
 
     $strtimezone = get_string("timezone");
     $strsavechanges = get_string("savechanges");
diff --git a/admin/tool/bloglevelupgrade/index.php b/admin/tool/bloglevelupgrade/index.php
index bd2a5310b37..823f2109194 100644
--- a/admin/tool/bloglevelupgrade/index.php
+++ b/admin/tool/bloglevelupgrade/index.php
@@ -102,8 +102,8 @@ if ($CFG->bloglevel == BLOG_COURSE_LEVEL || $CFG->bloglevel == BLOG_GROUP_LEVEL)
 function bloglevelupgrade_entries($blogentries, $forum, $cm, $groupid=-1) {
     $count = 0;
 
-    $forumcontext = get_context_instance(CONTEXT_MODULE, $cm->id);
-    $sitecontext = get_context_instance(CONTEXT_SYSTEM);
+    $forumcontext = context_module::instance($cm->id);
+    $sitecontext = context_system::instance();
 
     foreach ($blogentries as $blogentry) {
         $discussion = new stdClass();
diff --git a/admin/tool/capability/index.php b/admin/tool/capability/index.php
index e7e49d76fbf..3f9c58edd0c 100644
--- a/admin/tool/capability/index.php
+++ b/admin/tool/capability/index.php
@@ -29,7 +29,7 @@ require_once($CFG->libdir.'/adminlib.php');
 
 // Check permissions.
 require_login();
-$systemcontext = get_context_instance(CONTEXT_SYSTEM);
+$systemcontext = context_system::instance();
 require_capability('moodle/role:manage', $systemcontext);
 
 // Get URL parameters.
diff --git a/admin/tool/generator/index.php b/admin/tool/generator/index.php
index c747e311b99..577fefcf99d 100644
--- a/admin/tool/generator/index.php
+++ b/admin/tool/generator/index.php
@@ -28,7 +28,7 @@ require_once('locallib.php');
 
 
 require_login();
-$systemcontext = get_context_instance(CONTEXT_SYSTEM);
+$systemcontext = context_system::instance();
 require_capability('moodle/site:config', $systemcontext);
 if (!is_siteadmin()) {
     error('Only for admins');
diff --git a/admin/tool/generator/locallib.php b/admin/tool/generator/locallib.php
index 1eceb1aaee4..169f6436319 100644
--- a/admin/tool/generator/locallib.php
+++ b/admin/tool/generator/locallib.php
@@ -706,7 +706,7 @@ class generator {
                 shuffle($users);
                 $users_to_assign = array_slice($users, 0, $this->get('students_per_course'));
 
-                $context = get_context_instance(CONTEXT_COURSE, $courseid);
+                $context = context_course::instance($courseid);
                 foreach ($users_to_assign as $random_user) {
                     role_assign(5, $random_user, $context->id);
 
diff --git a/admin/tool/health/index.php b/admin/tool/health/index.php
index cc178309ce7..3966865c242 100644
--- a/admin/tool/health/index.php
+++ b/admin/tool/health/index.php
@@ -39,7 +39,7 @@
     $solution = optional_param('solution', 0, PARAM_PLUGIN);
 
     require_login();
-    require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+    require_capability('moodle/site:config', context_system::instance());
 
     $site = get_site();
 
diff --git a/admin/tool/innodb/index.php b/admin/tool/innodb/index.php
index 3e57e904fdd..06f4f6a5299 100644
--- a/admin/tool/innodb/index.php
+++ b/admin/tool/innodb/index.php
@@ -33,7 +33,7 @@ admin_externalpage_setup('toolinnodb');
 $confirm = optional_param('confirm', 0, PARAM_BOOL);
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 echo $OUTPUT->header();
 echo $OUTPUT->heading('Convert all MySQL tables from MYISAM to InnoDB');
diff --git a/admin/tool/qeupgradehelper/convertquiz.php b/admin/tool/qeupgradehelper/convertquiz.php
index f4176fc4cee..d12fc992703 100644
--- a/admin/tool/qeupgradehelper/convertquiz.php
+++ b/admin/tool/qeupgradehelper/convertquiz.php
@@ -33,7 +33,7 @@ $quizid = required_param('quizid', PARAM_INT);
 $confirmed = optional_param('confirmed', false, PARAM_BOOL);
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 tool_qeupgradehelper_require_upgraded();
 
 admin_externalpage_setup('qeupgradehelper', '', array(),
diff --git a/admin/tool/qeupgradehelper/cronsetup.php b/admin/tool/qeupgradehelper/cronsetup.php
index 58280a95b3f..2523ee5c565 100644
--- a/admin/tool/qeupgradehelper/cronsetup.php
+++ b/admin/tool/qeupgradehelper/cronsetup.php
@@ -30,7 +30,7 @@ require_once(dirname(__FILE__) . '/cronsetup_form.php');
 require_once($CFG->libdir . '/adminlib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 admin_externalpage_setup('qeupgradehelper', '', array(),
         tool_qeupgradehelper_url('cronsetup'));
diff --git a/admin/tool/qeupgradehelper/extracttestcase.php b/admin/tool/qeupgradehelper/extracttestcase.php
index d67fe6599a9..902418f1730 100644
--- a/admin/tool/qeupgradehelper/extracttestcase.php
+++ b/admin/tool/qeupgradehelper/extracttestcase.php
@@ -37,7 +37,7 @@ require_once($CFG->libdir . '/adminlib.php');
 
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 admin_externalpage_setup('qeupgradehelper', '', array(),
         tool_qeupgradehelper_url('extracttestcase'));
diff --git a/admin/tool/qeupgradehelper/index.php b/admin/tool/qeupgradehelper/index.php
index 2fe264216e7..776645a73ce 100644
--- a/admin/tool/qeupgradehelper/index.php
+++ b/admin/tool/qeupgradehelper/index.php
@@ -32,7 +32,7 @@ require_once(dirname(__FILE__) . '/locallib.php');
 require_once($CFG->libdir . '/adminlib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 admin_externalpage_setup('qeupgradehelper');
 
 $renderer = $PAGE->get_renderer('tool_qeupgradehelper');
diff --git a/admin/tool/qeupgradehelper/listpreupgrade.php b/admin/tool/qeupgradehelper/listpreupgrade.php
index e243dc3797d..ee15a094a80 100644
--- a/admin/tool/qeupgradehelper/listpreupgrade.php
+++ b/admin/tool/qeupgradehelper/listpreupgrade.php
@@ -30,7 +30,7 @@ require_once(dirname(__FILE__) . '/locallib.php');
 require_once($CFG->libdir . '/adminlib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 tool_qeupgradehelper_require_not_upgraded();
 
 admin_externalpage_setup('qeupgradehelper', '', array(), tool_qeupgradehelper_url(''));
diff --git a/admin/tool/qeupgradehelper/listtodo.php b/admin/tool/qeupgradehelper/listtodo.php
index 6e923ecd762..83062ea7a52 100644
--- a/admin/tool/qeupgradehelper/listtodo.php
+++ b/admin/tool/qeupgradehelper/listtodo.php
@@ -30,7 +30,7 @@ require_once(dirname(__FILE__) . '/locallib.php');
 require_once($CFG->libdir . '/adminlib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 tool_qeupgradehelper_require_upgraded();
 
 admin_externalpage_setup('qeupgradehelper', '', array(),
diff --git a/admin/tool/qeupgradehelper/listupgraded.php b/admin/tool/qeupgradehelper/listupgraded.php
index 8aa3dca78c0..187f75e984d 100644
--- a/admin/tool/qeupgradehelper/listupgraded.php
+++ b/admin/tool/qeupgradehelper/listupgraded.php
@@ -31,7 +31,7 @@ require_once(dirname(__FILE__) . '/locallib.php');
 require_once($CFG->libdir . '/adminlib.php');
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 tool_qeupgradehelper_require_upgraded();
 
 admin_externalpage_setup('qeupgradehelper', '', array(),
diff --git a/admin/tool/qeupgradehelper/resetquiz.php b/admin/tool/qeupgradehelper/resetquiz.php
index a3bf94a5ba0..1029cb23e24 100644
--- a/admin/tool/qeupgradehelper/resetquiz.php
+++ b/admin/tool/qeupgradehelper/resetquiz.php
@@ -32,7 +32,7 @@ $quizid = required_param('quizid', PARAM_INT);
 $confirmed = optional_param('confirmed', false, PARAM_BOOL);
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 tool_qeupgradehelper_require_upgraded();
 
 admin_externalpage_setup('qeupgradehelper', '', array(),
diff --git a/admin/tool/unsuproles/index.php b/admin/tool/unsuproles/index.php
index 144df3420e8..c6d2f361055 100644
--- a/admin/tool/unsuproles/index.php
+++ b/admin/tool/unsuproles/index.php
@@ -29,7 +29,7 @@ require_once($CFG->libdir.'/adminlib.php');
 
 $action = optional_param('action', '', PARAM_ALPHANUMEXT);
 
-$syscontext = get_context_instance(CONTEXT_SYSTEM);
+$syscontext = context_system::instance();
 
 require_login();
 admin_externalpage_setup('toolunsuproles'); // checks permissions specified in settings.php
diff --git a/admin/tool/uploaduser/index.php b/admin/tool/uploaduser/index.php
index ec692e227fa..b9c645aea4f 100644
--- a/admin/tool/uploaduser/index.php
+++ b/admin/tool/uploaduser/index.php
@@ -40,7 +40,7 @@ raise_memory_limit(MEMORY_HUGE);
 
 require_login();
 admin_externalpage_setup('tooluploaduser');
-require_capability('moodle/site:uploadusers', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:uploadusers', context_system::instance());
 
 $struserrenamed             = get_string('userrenamed', 'tool_uploaduser');
 $strusernotrenamedexists    = get_string('usernotrenamedexists', 'error');
@@ -731,7 +731,7 @@ if ($formdata = $mform2->is_cancelled()) {
             $usersnew++;
 
             // make sure user context exists
-            get_context_instance(CONTEXT_USER, $user->id);
+            context_user::instance($user->id);
 
             events_trigger('user_created', $user);
 
@@ -805,7 +805,7 @@ if ($formdata = $mform2->is_cancelled()) {
                 $ccache[$shortname]->groups = null;
             }
             $courseid      = $ccache[$shortname]->id;
-            $coursecontext = get_context_instance(CONTEXT_COURSE, $courseid);
+            $coursecontext = context_course::instance($courseid);
             if (!isset($manualcache[$courseid])) {
                 $manualcache[$courseid] = false;
                 if ($manual) {
diff --git a/admin/tool/uploaduser/locallib.php b/admin/tool/uploaduser/locallib.php
index 2350b14aca9..928b13e1581 100644
--- a/admin/tool/uploaduser/locallib.php
+++ b/admin/tool/uploaduser/locallib.php
@@ -341,7 +341,7 @@ function uu_supported_auths() {
  */
 function uu_allowed_roles() {
     // let's cheat a bit, frontpage is guaranteed to exist and has the same list of roles ;-)
-    $roles = get_assignable_roles(get_context_instance(CONTEXT_COURSE, SITEID), ROLENAME_ORIGINALANDSHORT);
+    $roles = get_assignable_roles(context_course::instance(SITEID), ROLENAME_ORIGINALANDSHORT);
     return array_reverse($roles, true);
 }
 
@@ -350,7 +350,7 @@ function uu_allowed_roles() {
  * @return array
  */
 function uu_allowed_roles_cache() {
-    $allowedroles = get_assignable_roles(get_context_instance(CONTEXT_COURSE, SITEID), ROLENAME_SHORT);
+    $allowedroles = get_assignable_roles(context_course::instance(SITEID), ROLENAME_SHORT);
     foreach ($allowedroles as $rid=>$rname) {
         $rolecache[$rid] = new stdClass();
         $rolecache[$rid]->id   = $rid;
diff --git a/admin/tool/uploaduser/picture.php b/admin/tool/uploaduser/picture.php
index 781b32dfd21..f0f15117f6f 100644
--- a/admin/tool/uploaduser/picture.php
+++ b/admin/tool/uploaduser/picture.php
@@ -38,7 +38,7 @@ admin_externalpage_setup('tooluploaduserpictures');
 
 require_login();
 
-require_capability('moodle/site:uploadusers', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:uploadusers', context_system::instance());
 
 $site = get_site();
 
@@ -247,7 +247,7 @@ function process_file ($file, $userfield, $overwrite) {
  * @return mixed new unique revision number or false if not saved
  */
 function my_save_profile_image($id, $originalfile) {
-    $context = get_context_instance(CONTEXT_USER, $id);
+    $context = context_user::instance($id);
     return process_new_icon($context, 'user', 'icon', 0, $originalfile);
 }
 
diff --git a/admin/tool/xmldb/index.php b/admin/tool/xmldb/index.php
index e5a61477e45..8feef19d104 100644
--- a/admin/tool/xmldb/index.php
+++ b/admin/tool/xmldb/index.php
@@ -51,7 +51,7 @@ if (!isset($SESSION->xmldb)) {
 $site = get_site();
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 // Body of the script, based on action, we delegate the work
 $action = optional_param ('action', 'main_view', PARAM_ALPHAEXT);
diff --git a/admin/user.php b/admin/user.php
index 56e457e27c1..5abb3b02594 100644
--- a/admin/user.php
+++ b/admin/user.php
@@ -19,7 +19,7 @@
 
     admin_externalpage_setup('editusers');
 
-    $sitecontext = get_context_instance(CONTEXT_SYSTEM);
+    $sitecontext = context_system::instance();
     $site = get_site();
 
     if (!has_capability('moodle/user:update', $sitecontext) and !has_capability('moodle/user:delete', $sitecontext)) {
diff --git a/admin/user/user_bulk_cohortadd.php b/admin/user/user_bulk_cohortadd.php
index f97216d8977..1e32564fe59 100644
--- a/admin/user/user_bulk_cohortadd.php
+++ b/admin/user/user_bulk_cohortadd.php
@@ -32,7 +32,7 @@ $sort = optional_param('sort', 'fullname', PARAM_ALPHA);
 $dir  = optional_param('dir', 'asc', PARAM_ALPHA);
 
 admin_externalpage_setup('userbulk');
-require_capability('moodle/cohort:assign', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/cohort:assign', context_system::instance());
 
 $users = $SESSION->bulk_users;
 
diff --git a/admin/user/user_bulk_confirm.php b/admin/user/user_bulk_confirm.php
index c7ba604ea5e..1483e203ce2 100644
--- a/admin/user/user_bulk_confirm.php
+++ b/admin/user/user_bulk_confirm.php
@@ -10,7 +10,7 @@ $confirm = optional_param('confirm', 0, PARAM_BOOL);
 
 require_login();
 admin_externalpage_setup('userbulk');
-require_capability('moodle/user:update', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/user:update', context_system::instance());
 
 $return = $CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk.php';
 
diff --git a/admin/user/user_bulk_delete.php b/admin/user/user_bulk_delete.php
index a8b6705ce8f..f8ac0c95343 100644
--- a/admin/user/user_bulk_delete.php
+++ b/admin/user/user_bulk_delete.php
@@ -10,7 +10,7 @@ $confirm = optional_param('confirm', 0, PARAM_BOOL);
 
 require_login();
 admin_externalpage_setup('userbulk');
-require_capability('moodle/user:delete', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/user:delete', context_system::instance());
 
 $return = $CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk.php';
 
diff --git a/admin/user/user_bulk_download.php b/admin/user/user_bulk_download.php
index 27fc9b924ad..c60c663cc07 100644
--- a/admin/user/user_bulk_download.php
+++ b/admin/user/user_bulk_download.php
@@ -10,7 +10,7 @@ $format = optional_param('format', '', PARAM_ALPHA);
 
 require_login();
 admin_externalpage_setup('userbulk');
-require_capability('moodle/user:update', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/user:update', context_system::instance());
 
 $return = $CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk.php';
 
diff --git a/admin/user/user_bulk_enrol.php b/admin/user/user_bulk_enrol.php
index 10e39fc1ed0..21ad105e257 100644
--- a/admin/user/user_bulk_enrol.php
+++ b/admin/user/user_bulk_enrol.php
@@ -13,7 +13,7 @@ $dir  = optional_param('dir', 'asc', PARAM_ALPHA);       //Order to sort (ASC)
 
 require_login();
 admin_externalpage_setup('userbulk');
-require_capability('moodle/role:assign', get_context_instance(CONTEXT_SYSTEM)); //TODO: use some enrol cap
+require_capability('moodle/role:assign', context_system::instance()); //TODO: use some enrol cap
 $return = $CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk.php';
 //If no users selected then return to user_bulk.php
 if (empty($SESSION->bulk_users)) {
@@ -86,13 +86,13 @@ if(!empty($processed)) {
          */
         $ids = explode(',', $info);
         if(!empty($ids[2])) {
-            $context = get_context_instance(CONTEXT_COURSE, $ids[1]);
+            $context = context_course::instance($ids[1]);
             role_assign(5, $ids[0], $context->id); //TODO: horrible!!
         } else {
             if( empty($ids[1] ) ) {
                 continue;
             }
-            $context = get_context_instance(CONTEXT_COURSE, $ids[1]);
+            $context = context_course::instance($ids[1]);
             role_unassign(5, $ids[0], $context->id);
         }
     }
diff --git a/admin/user/user_bulk_forcepasswordchange.php b/admin/user/user_bulk_forcepasswordchange.php
index d67c9427aec..203f69c47ee 100644
--- a/admin/user/user_bulk_forcepasswordchange.php
+++ b/admin/user/user_bulk_forcepasswordchange.php
@@ -11,7 +11,7 @@ $confirm = optional_param('confirm', 0, PARAM_BOOL);
 
 require_login();
 admin_externalpage_setup('userbulk');
-require_capability('moodle/user:update', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/user:update', context_system::instance());
 
 $return = $CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk.php';
 
diff --git a/admin/user/user_bulk_forms.php b/admin/user/user_bulk_forms.php
index fa119be5812..0f7c25c3261 100644
--- a/admin/user/user_bulk_forms.php
+++ b/admin/user/user_bulk_forms.php
@@ -9,7 +9,7 @@ class user_bulk_action_form extends moodleform {
 
         $mform =& $this->_form;
 
-        $syscontext = get_context_instance(CONTEXT_SYSTEM);
+        $syscontext = context_system::instance();
         $actions = array(0=>get_string('choose').'...');
         if (has_capability('moodle/user:update', $syscontext)) {
             $actions[1] = get_string('confirm');
diff --git a/admin/user/user_bulk_message.php b/admin/user/user_bulk_message.php
index a69546e48ac..83161a7d554 100644
--- a/admin/user/user_bulk_message.php
+++ b/admin/user/user_bulk_message.php
@@ -9,7 +9,7 @@ $confirm = optional_param('confirm', 0, PARAM_BOOL);
 
 require_login();
 admin_externalpage_setup('userbulk');
-require_capability('moodle/site:readallmessages', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:readallmessages', context_system::instance());
 
 $return = $CFG->wwwroot.'/'.$CFG->admin.'/user/user_bulk.php';
 
diff --git a/admin/webservice/forms.php b/admin/webservice/forms.php
index fef6a753fe8..bffaba9dc92 100644
--- a/admin/webservice/forms.php
+++ b/admin/webservice/forms.php
@@ -82,7 +82,7 @@ class external_service_form extends moodleform {
         }
 
         // Prepare the list of capabilities to choose from
-        $systemcontext = get_context_instance(CONTEXT_SYSTEM);
+        $systemcontext = context_system::instance();
         $allcapabilities = fetch_context_capabilities($systemcontext);
         $capabilitychoices = array();
         $capabilitychoices['norequiredcapability'] = get_string('norequiredcapability',
@@ -216,7 +216,7 @@ class web_service_token_form extends moodleform {
         //service selector
         $services = $DB->get_records('external_services');
         $options = array();
-        $systemcontext = get_context_instance(CONTEXT_SYSTEM);
+        $systemcontext = context_system::instance();
         foreach ($services as $serviceid => $service) {
             //check that the user has the required capability
             //(only for generation by the profile page)
diff --git a/admin/webservice/protocols.php b/admin/webservice/protocols.php
index 9e7fcfb1548..c5cc1949bf4 100644
--- a/admin/webservice/protocols.php
+++ b/admin/webservice/protocols.php
@@ -31,7 +31,7 @@ $PAGE->set_url('/' . $CFG->admin . '/webservice/protocols.php');
 //TODO: disable the blocks here or better make the page layout default to no blocks!
 
 require_login();
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 $returnurl = $CFG->wwwroot . "/" . $CFG->admin . "/settings.php?section=webserviceprotocols";
 
diff --git a/admin/webservice/tokens.php b/admin/webservice/tokens.php
index 7e1766325b6..60ea271005f 100644
--- a/admin/webservice/tokens.php
+++ b/admin/webservice/tokens.php
@@ -42,7 +42,7 @@ if ($node && $newnode) {
     $newnode->make_active();
 }
 
-require_capability('moodle/site:config', get_context_instance(CONTEXT_SYSTEM));
+require_capability('moodle/site:config', context_system::instance());
 
 $tokenlisturl = new moodle_url("/" . $CFG->admin . "/settings.php", array('section' => 'webservicetokens'));
 
@@ -83,7 +83,7 @@ switch ($action) {
                 // either move most of webservicelib.php functions into externallib.php
                 // (create externalmanager class) MDL-23523
                 external_generate_token(EXTERNAL_TOKEN_PERMANENT, $data->service,
-                        $data->user, get_context_instance(CONTEXT_SYSTEM),
+                        $data->user, context_system::instance(),
                         $data->validuntil, $data->iprestriction);
                 redirect($tokenlisturl);
             }