diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index f50dd39..bfb7d33 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -206,6 +206,13 @@ const LANGUAGE_NOT_APPLICABLE = 'zxx';
 const LANGUAGE_MULTIPLE = 'mul';
 
 /**
+ * The language code used when referring to all languages.
+ *
+ * @todo W3C uses this for 'Allar', need to find a better code.
+ */
+const LANGUAGE_ALL = 'all';
+
+/**
  * The type of language used to define the content language.
  */
 const LANGUAGE_TYPE_CONTENT = 'language_content';
@@ -231,6 +238,16 @@ const LANGUAGE_LTR = 0;
 const LANGUAGE_RTL = 1;
 
 /**
+ * Flag for language list extension to add disabled languages.
+ */
+const LANGUAGE_ADD_DISABLED = 1;
+
+/**
+ * Flag for language list extension to add locked languages.
+ */
+const LANGUAGE_ADD_LOCKED = 2;
+
+/**
  * Time of the current request in seconds elapsed since the Unix Epoch.
  *
  * This differs from $_SERVER['REQUEST_TIME'], which is stored as a float
@@ -2502,43 +2519,50 @@ function language_multilingual() {
 /**
  * Returns a list of configured languages.
  *
- * @param $only_enabled
- *   (optional) Whether to return only enabled languages.
+ * @param $flags
+ *   (optional) A combination of LANGUAGE_ADD_DISABLED and LANGUAGE_ADD_LOCKED
+ *   depending on the need for disabled and locked (special) languages in the
+ *   returned list.
  *
  * @return
  *   An associative array of languages, keyed by the language code, ordered by
  *   weight ascending and name ascending.
  */
-function language_list($only_enabled = FALSE) {
+function language_list($flags = NULL) {
+
   $languages = &drupal_static(__FUNCTION__);
+
   // Initialize master language list.
   if (!isset($languages)) {
-    // Initialize local language list caches.
-    $languages = array('all' => array(), 'enabled' => array());
+    // Initialize local language list cache.
+    $languages = array();
 
     // Fill in master language list based on current configuration.
     $default = language_default();
     if (language_multilingual() || module_exists('language')) {
       // Use language module configuration if available.
-      $languages['all'] = db_query('SELECT * FROM {language} ORDER BY weight ASC, name ASC')->fetchAllAssoc('langcode');
+      $languages = db_query('SELECT *, 0 as `default` FROM {language} ORDER BY weight ASC, name ASC')->fetchAllAssoc('langcode');
+      $languages[$default->langcode]->default = 1;
     }
     else {
       // No language module, so use the default language only.
-      $languages['all'][$default->langcode] = $default;
+      $languages[$default->langcode] = $default;
     }
+  }
 
-    // Initialize default property so callers have an easy reference and can
-    // save the same object without data loss. Also fill in the filtered list
-    // of enabled languages only.
-    foreach ($languages['all'] as $langcode => $language) {
-      $languages['all'][$langcode]->default = ($langcode == $default->langcode);
-      if ($language->enabled) {
-        $languages['enabled'][$langcode] = $languages['all'][$langcode];
-      }
+  // Filter the full list of languages based on the criteria in $flags. By
+  // default we remove the disabled and locked languages, but the caller may
+  // request for those languages to be added as well.
+  $filtered_languages = array();
+  foreach ($languages as $langcode => $language) {
+    if ((!$language->enabled && !($flags & LANGUAGE_ADD_DISABLED)) ||
+        ($language->locked && !($flags & LANGUAGE_ADD_LOCKED))) {
+      continue;
     }
+    $filtered_languages[$langcode] = $language;
   }
 
-  return $only_enabled ? $languages['enabled'] : $languages['all'];
+  return $filtered_languages;
 }
 
 /**
@@ -2551,7 +2575,7 @@ function language_list($only_enabled = FALSE) {
  *   A fully-populated language object or FALSE.
  */
 function language_load($langcode) {
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
   return isset($languages[$langcode]) ? $languages[$langcode] : FALSE;
 }
 
@@ -2591,6 +2615,7 @@ function language_default() {
     'direction' => 0,
     'enabled' => 1,
     'weight' => 0,
+    'locked' => 0,
   ));
   $default->default = TRUE;
   return $default;
diff --git a/core/includes/language.inc b/core/includes/language.inc
index 2c46c76..6d9f156 100644
--- a/core/includes/language.inc
+++ b/core/includes/language.inc
@@ -338,8 +338,7 @@ function language_negotiation_method_invoke($method_id, $method = NULL) {
   if (!isset($results[$method_id])) {
     global $user;
 
-    // Get the enabled languages only.
-    $languages = language_list(TRUE);
+    $languages = language_list();
 
     if (!isset($method)) {
       $negotiation_info = language_negotiation_info();
diff --git a/core/includes/update.inc b/core/includes/update.inc
index 2715fdf..0b67646 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -195,9 +195,10 @@ function update_prepare_d8_language() {
     update_module_add_to_system($modules);
     update_module_enable($modules);
 
-    // Rename 'language' column to 'langcode'.
+    // Rename 'language' column to 'langcode', add locked column.
     require_once DRUPAL_ROOT . '/core/modules/language/language.install';
     language_update_8000();
+    language_update_8001();
   }
 }
 
diff --git a/core/modules/field/field.multilingual.inc b/core/modules/field/field.multilingual.inc
index f054bf1..2290f67 100644
--- a/core/modules/field/field.multilingual.inc
+++ b/core/modules/field/field.multilingual.inc
@@ -165,14 +165,14 @@ function _field_language_suggestion($available_langcodes, $langcode_suggestion,
 /**
  * Returns available content language codes.
  *
- * The language codes that may be associated to fields include
- * LANGUAGE_NOT_SPECIFIED.
+ * The languages that may be associated to fields may include
+ * LANGUAGE_NOT_SPECIFIED, LANGUAGE_NOT_APPLICABLE and LANGUAGE_MULTIPLE.
  *
  * @return
  *   An array of language codes.
  */
 function field_content_languages() {
-  return array_keys(language_list() + array(LANGUAGE_NOT_SPECIFIED => NULL));
+  return array_keys(language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED));
 }
 
 /**
diff --git a/core/modules/language/language.admin.inc b/core/modules/language/language.admin.inc
index e341094..4c7b461 100644
--- a/core/modules/language/language.admin.inc
+++ b/core/modules/language/language.admin.inc
@@ -10,7 +10,7 @@
  */
 function language_admin_overview_form($form, &$form_state) {
   drupal_static_reset('language_list');
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
   $default = language_default();
 
   $form['languages'] = array(
@@ -29,8 +29,24 @@ function language_admin_overview_form($form, &$form_state) {
 
   foreach ($languages as $langcode => $language) {
     $form['languages'][$langcode]['#weight'] = $language->weight;
+    $title = check_plain($language->name);
+    $description = '';
+    switch ($langcode) {
+      case LANGUAGE_NOT_APPLICABLE:
+        $description = t('For language independent content.');
+        break;
+      case LANGUAGE_NOT_SPECIFIED:
+        $description = t('Use this when the language is not (yet) known.');
+        break;
+      case LANGUAGE_MULTIPLE:
+        $description = t('Use this when multiple languages can be assigned, such as a multilingual PDF.');
+        break;
+    }
+    if (!empty($description)) {
+      $title .= '<div class="description">' . $description . '</div>';
+    }
     $form['languages'][$langcode]['name'] = array(
-      '#markup' => check_plain($language->name),
+      '#markup' => $title,
     );
     $form['languages'][$langcode]['enabled'] = array(
       '#type' => 'checkbox',
@@ -61,17 +77,22 @@ function language_admin_overview_form($form, &$form_state) {
       '#theme_wrappers' => array('language_admin_operations'),
       '#weight' => 100,
     );
-    $form['languages'][$langcode]['operations']['edit'] = array(
-      '#type' => 'link',
-      '#title' => t('edit'),
-      '#href' => 'admin/config/regional/language/edit/' . $langcode,
-    );
-    $form['languages'][$langcode]['operations']['delete'] = array(
-      '#type' => 'link',
-      '#title' => t('delete'),
-      '#href' => 'admin/config/regional/language/delete/' . $langcode,
-      '#access' => $langcode != $default->langcode,
-    );
+    if (empty($language->locked)) {
+      $form['languages'][$langcode]['operations']['edit'] = array(
+        '#type' => 'link',
+        '#title' => t('edit'),
+        '#href' => 'admin/config/regional/language/edit/' . $langcode,
+      );
+      $form['languages'][$langcode]['operations']['delete'] = array(
+        '#type' => 'link',
+        '#title' => t('delete'),
+        '#href' => 'admin/config/regional/language/delete/' . $langcode,
+        '#access' => $langcode != $default->langcode,
+      );
+    }
+    else{
+      $form['languages'][$langcode]['default']['#disabled'] = TRUE;
+    }
   }
 
   $form['actions'] = array('#type' => 'actions');
@@ -148,7 +169,7 @@ function theme_language_admin_overview_form_table($variables) {
  * Process language overview form submissions, updating existing languages.
  */
 function language_admin_overview_form_submit($form, &$form_state) {
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
   $old_default = language_default();
 
   foreach ($languages as $langcode => $language) {
@@ -314,7 +335,7 @@ function language_admin_add_custom_form_validate($form, &$form_state) {
     // Reuse the editing form validation routine if we add a custom language.
     language_admin_edit_form_validate($form, $form_state);
 
-    $languages = language_list();
+    $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
     if (isset($languages[$langcode])) {
      form_set_error('langcode', t('The language %language (%langcode) already exists.', array('%language' => $languages[$langcode]->name, '%langcode' => $langcode)));
     }
@@ -374,7 +395,7 @@ function language_admin_edit_form_validate($form, &$form_state) {
  */
 function language_admin_edit_form_submit($form, &$form_state) {
   // Prepare a language object for saving.
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   $langcode = $form_state['values']['langcode'];
   $language = $languages[$langcode];
   $language->name = $form_state['values']['name'];
@@ -395,7 +416,7 @@ function language_admin_delete_form($form, &$form_state, $language) {
   }
 
   // For other languages, warn the user that data loss is ahead.
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
 
   if (!isset($languages[$langcode])) {
     drupal_not_found();
@@ -412,7 +433,7 @@ function language_admin_delete_form($form, &$form_state, $language) {
  */
 function language_admin_delete_form_submit($form, &$form_state) {
   $langcode = $form_state['values']['langcode'];
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   $language = $languages[$langcode];
 
   $success = language_delete($langcode);
@@ -430,7 +451,7 @@ function language_admin_delete_form_submit($form, &$form_state) {
  */
 function language_admin_predefined_list() {
   include_once DRUPAL_ROOT . '/core/includes/standard.inc';
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   $predefined = standard_language_list();
   foreach ($predefined as $key => $value) {
     if (isset($languages[$key])) {
@@ -694,8 +715,7 @@ function language_negotiation_configure_url_form($form, &$form_state) {
     ),
   );
 
-  // Get the enabled languages only.
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   $prefixes = language_negotiation_url_prefixes();
   $domains = language_negotiation_url_domains();
   foreach ($languages as $langcode => $language) {
@@ -731,8 +751,7 @@ function language_negotiation_configure_url_form($form, &$form_state) {
  * the prefix and domain are only blank for the default.
  */
 function language_negotiation_configure_url_form_validate($form, &$form_state) {
-  // Get the enabled languages only.
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
 
   // Count repeated values for uniqueness check.
   $count = array_count_values($form_state['values']['prefix']);
diff --git a/core/modules/language/language.install b/core/modules/language/language.install
index 92f61a0..fbd130d 100644
--- a/core/modules/language/language.install
+++ b/core/modules/language/language.install
@@ -12,8 +12,13 @@
  * system on multilingual sites without needing any preliminary configuration.
  */
 function language_install() {
-  // Add the default language to the database too.
+  // Add the default language at first so that language_list() returns this in
+  // language_special_languages().
   language_save(language_default());
+  $languages = language_special_languages();
+  foreach ($languages as $language) {
+    language_save($language);
+  }
 
   // Enable URL language detection for each configurable language type.
   require_once DRUPAL_ROOT . '/core/includes/language.inc';
@@ -23,6 +28,43 @@ function language_install() {
 }
 
 /**
+ * List of special languages to install on a site.
+ *
+ * @return
+ *   An array of language objects.
+ */
+function language_special_languages() {
+  $locked_language = array(
+    'default' => FALSE,
+    'locked' => TRUE,
+    'enabled' => TRUE,
+  );
+  $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
+
+  // Language list is ordered by weight, get the biggest one.
+  $keys = array_keys($languages);
+  $max_weight = $languages[array_pop($keys)]->weight;
+  $languages = array();
+
+  $languages[LANGUAGE_NOT_SPECIFIED] = (object) (array(
+    'langcode' => LANGUAGE_NOT_SPECIFIED,
+    'name' => t('Not specified'),
+    'weight' => ++$max_weight,
+  ) + $locked_language);
+  $languages[LANGUAGE_NOT_APPLICABLE] = (object) (array(
+    'langcode' => LANGUAGE_NOT_APPLICABLE,
+    'name' => t('Not applicable'),
+    'weight' => ++$max_weight,
+  ) + $locked_language);
+  $languages[LANGUAGE_MULTIPLE] = (object) (array(
+    'langcode' => LANGUAGE_MULTIPLE,
+    'name' => t('Multiple'),
+    'weight' => ++$max_weight,
+  ) + $locked_language);
+  return $languages;
+}
+
+/**
  * Implements hook_uninstall().
  */
 function language_uninstall() {
@@ -88,6 +130,13 @@ function language_schema() {
         'default' => 0,
         'description' => 'Weight, used in lists of languages.',
       ),
+      'locked' => array(
+        'type' => 'int',
+        'size' => 'tiny',
+        'not null' => TRUE,
+        'default' => 0,
+        'description' => 'A boolean indicating whether the administrator can edit or delete the language.',
+      ),
     ),
     'primary key' => array('langcode'),
     'indexes' => array(
@@ -124,3 +173,49 @@ function language_update_8000() {
     variable_set('language_default', $language_default);
   }
 }
+
+/**
+ * Adds the locked column and saves the special languages.
+ */
+function language_update_8001() {
+  if (!db_field_exists('language', 'locked')) {
+    $locked_spec = array(
+      'type' => 'int',
+      'size' => 'tiny',
+      'not null' => TRUE,
+      'default' => 0,
+      'description' => 'A boolean indicating whether the administrator can edit or delete the language.',
+    );
+    db_add_field('language', 'locked', $locked_spec);
+
+    $max_weight = db_query('SELECT MAX(weight) FROM {language}')->fetchField();
+    $languages = array();
+    $languages[LANGUAGE_NOT_SPECIFIED] = array(
+      'langcode' => LANGUAGE_NOT_SPECIFIED,
+      'name' => 'Not specified',
+      'weight' => ++$max_weight,
+    );
+    $languages[LANGUAGE_NOT_APPLICABLE] = array(
+      'langcode' => LANGUAGE_NOT_APPLICABLE,
+      'name' => 'Not applicable',
+      'weight' => ++$max_weight,
+    );
+    $languages[LANGUAGE_MULTIPLE] = array(
+      'langcode' => LANGUAGE_MULTIPLE,
+      'name' => 'Multiple',
+      'weight' => ++$max_weight,
+    );
+    foreach ($languages as $language) {
+      db_insert('language')
+        ->fields(array(
+          'langcode' => $language['langcode'],
+          'name' => $language['name'],
+          'weight' => $language['weight'],
+          // These languages are locked, default to enabled.
+          'locked' => 1,
+          'enabled' => 1,
+        ))
+        ->execute();
+    }
+  }
+}
diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index 34f1a59..4e6c990 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -24,7 +24,7 @@ function language_help($path, $arg) {
       return $output;
 
     case 'admin/config/regional/language':
-      return '<p>' . t('With multiple languages enabled, registered users may select their preferred language and authors can assign a specific language to content.') . '</p>';
+      return '<p>' . t('With multiple languages enabled, registered users can select their preferred language and authors can assign a specific language to content.') . '</p>';
 
     case 'admin/config/regional/language/add':
       return '<p>' . t('Add a language to be supported by your site. If your desired language is not available, pick <em>Custom language...</em> at the end and provide a language code and other details manually.') . '</p>';
@@ -77,14 +77,16 @@ function language_menu() {
     'title' => 'Edit language',
     'page callback' => 'drupal_get_form',
     'page arguments' => array('language_admin_edit_form', 5),
-    'access arguments' => array('administer languages'),
+    'access callback' => 'language_access_language_edit_or_delete',
+    'access arguments' => array(5),
     'file' => 'language.admin.inc',
   );
   $items['admin/config/regional/language/delete/%language'] = array(
     'title' => 'Confirm delete',
     'page callback' => 'drupal_get_form',
     'page arguments' => array('language_admin_delete_form', 5),
-    'access arguments' => array('administer languages'),
+    'access callback' => 'language_access_language_edit_or_delete',
+    'access arguments' => array(5),
     'file' => 'language.admin.inc',
   );
 
@@ -119,6 +121,13 @@ function language_menu() {
 }
 
 /**
+ * Editing or deleting locked languages should not be possible.
+ */
+function language_access_language_edit_or_delete($language) {
+  return !$language->locked && user_access('administer languages');
+}
+
+/**
  * Implements hook_permission().
  */
 function language_permission() {
@@ -192,11 +201,10 @@ function language_save($language) {
   }
 
   // Update language count based on enabled language count.
-  variable_set('language_count', db_query('SELECT COUNT(langcode) FROM {language} WHERE enabled = 1')->fetchField());
+  variable_set('language_count', db_query('SELECT COUNT(langcode) FROM {language} WHERE enabled = 1 AND locked = 0')->fetchField());
 
   // Kill the static cache in language_list().
   drupal_static_reset('language_list');
-
   return $language;
 }
 
@@ -209,8 +217,8 @@ function language_save($language) {
  *   TRUE if language is successfully deleted. Otherwise FALSE.
  */
 function language_delete($langcode) {
-  $languages = language_list();
-  if (isset($languages[$langcode])) {
+  $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
+  if (isset($languages[$langcode]) && !$languages[$langcode]->locked) {
     $language = $languages[$langcode];
 
     module_invoke_all('language_delete', $language);
@@ -394,6 +402,10 @@ function language_modules_disabled($modules) {
  * Implements hook_language_insert().
  */
 function language_language_insert($language) {
+  if (!empty($language->locked)) {
+    return;
+  }
+
   language_negotiation_include();
 
   // Add new language to the list of language prefixes.
@@ -411,6 +423,10 @@ function language_language_insert($language) {
  * Implements hook_language_update().
  */
 function language_language_update($language) {
+  if (!empty($language->locked)) {
+    return;
+  }
+
   language_negotiation_include();
 
   // If the language is the default, then ensure that no other languages have
@@ -527,15 +543,16 @@ function language_url_outbound_alter(&$path, &$options, $original_path) {
       $callbacks = array_keys($callbacks);
     }
 
+    // No language dependent path allowed in this mode.
+    if (empty($callbacks)) {
+      unset($options['language']);
+      return;
+    }
+
     foreach ($callbacks as $callback) {
       if (function_exists($callback)) {
         $callback($path, $options);
       }
     }
-
-    // No language dependent path allowed in this mode.
-    if (empty($callbacks)) {
-      unset($options['language']);
-    }
   }
 }
diff --git a/core/modules/language/language.negotiation.inc b/core/modules/language/language.negotiation.inc
index c90457f..401b528 100644
--- a/core/modules/language/language.negotiation.inc
+++ b/core/modules/language/language.negotiation.inc
@@ -294,8 +294,7 @@ function language_url_fallback($language = NULL, $language_type = LANGUAGE_TYPE_
  * Translation links may be provided by other modules.
  */
 function language_switcher_url($type, $path) {
-  // Get the enabled languages only.
-  $languages = language_list(TRUE);
+  $languages = language_list();
   $links = array();
 
   foreach ($languages as $language) {
@@ -317,8 +316,7 @@ function language_switcher_session($type, $path) {
   $param = variable_get('language_negotiation_session_param', 'language');
   $language_query = isset($_SESSION[$param]) ? $_SESSION[$param] : $GLOBALS[$type]->langcode;
 
-  // Get the enabled languages only.
-  $languages = language_list(TRUE);
+  $languages = language_list();
   $links = array();
 
   $query = $_GET;
@@ -354,8 +352,7 @@ function language_url_rewrite_url(&$path, &$options) {
   $languages = &$drupal_static_fast['languages'];
 
   if (!isset($languages)) {
-    // Get the enabled languages only.
-    $languages = language_list(TRUE);
+    $languages = language_list();
     $languages = array_flip(array_keys($languages));
   }
 
@@ -365,7 +362,7 @@ function language_url_rewrite_url(&$path, &$options) {
     $options['language'] = $language_url;
   }
   // We allow only enabled languages here.
-  elseif (!isset($languages[$options['language']->langcode])) {
+  elseif (is_object($options['language']) && !isset($languages[$options['language']->langcode])) {
     unset($options['language']);
     return;
   }
@@ -374,7 +371,7 @@ function language_url_rewrite_url(&$path, &$options) {
     switch (variable_get('language_negotiation_url_part', LANGUAGE_NEGOTIATION_URL_PREFIX)) {
       case LANGUAGE_NEGOTIATION_URL_DOMAIN:
         $domains = language_negotiation_url_domains();
-        if (!empty($domains[$options['language']->langcode])) {
+        if (is_object($options['language']) && !empty($domains[$options['language']->langcode])) {
           // Ask for an absolute URL with our modified base_url.
           global $is_https;
           $url_scheme = ($is_https) ? 'https://' : 'http://';
@@ -393,7 +390,7 @@ function language_url_rewrite_url(&$path, &$options) {
 
       case LANGUAGE_NEGOTIATION_URL_PREFIX:
         $prefixes = language_negotiation_url_prefixes();
-        if (!empty($prefixes[$options['language']->langcode])) {
+        if (is_object($options['language']) &&!empty($prefixes[$options['language']->langcode])) {
           $options['prefix'] = $prefixes[$options['language']->langcode] . '/';
         }
         break;
@@ -440,8 +437,7 @@ function language_url_rewrite_session(&$path, &$options) {
   if (!isset($query_rewrite)) {
     global $user;
     if (!$user->uid) {
-      // Get the enabled languages only.
-      $languages = language_list(TRUE);
+      $languages = language_list();
       $query_param = check_plain(variable_get('language_negotiation_session_param', 'language'));
       $query_value = isset($_GET[$query_param]) ? check_plain($_GET[$query_param]) : NULL;
       $query_rewrite = isset($languages[$query_value]) && language_negotiation_method_enabled(LANGUAGE_NEGOTIATION_SESSION);
diff --git a/core/modules/language/language.test b/core/modules/language/language.test
index 6c64c29..bd1130d 100644
--- a/core/modules/language/language.test
+++ b/core/modules/language/language.test
@@ -122,7 +122,7 @@ class LanguageListTest extends DrupalWebTestCase {
     $this->assertResponse(404, t('Language no longer found.'));
     // Make sure the "language_count" variable has been updated correctly.
     drupal_static_reset('language_list');
-    $enabled_languages = language_list(TRUE);
+    $enabled_languages = language_list();
     $this->assertEqual(variable_get('language_count', 1), count($enabled_languages), t('Language count is correct.'));
     // Delete a disabled language.
     // Disable an enabled language.
@@ -133,7 +133,7 @@ class LanguageListTest extends DrupalWebTestCase {
     $this->assertNoFieldChecked('edit-languages-fr-enabled', t('French language disabled.'));
     // Get the count of enabled languages.
     drupal_static_reset('language_list');
-    $enabled_languages = language_list(TRUE);
+    $enabled_languages = language_list();
     // Delete the disabled language.
     $this->drupalPost('admin/config/regional/language/delete/fr', array(), t('Delete'));
     // We need raw here because %language and %langcode will add HTML.
diff --git a/core/modules/locale/locale.admin.inc b/core/modules/locale/locale.admin.inc
index d74f714..0e4a94b 100644
--- a/core/modules/locale/locale.admin.inc
+++ b/core/modules/locale/locale.admin.inc
@@ -45,9 +45,7 @@ function locale_date_format_language_overview_page() {
     array('data' => t('Operations'), 'colspan' => '2'),
   );
 
-  // Get the enabled languages only.
-  $languages = language_list(TRUE);
-
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   foreach ($languages as $langcode => $language) {
     $row = array();
     $row[] = $language->name;
diff --git a/core/modules/locale/locale.bulk.inc b/core/modules/locale/locale.bulk.inc
index ed3d3a6..997500d 100644
--- a/core/modules/locale/locale.bulk.inc
+++ b/core/modules/locale/locale.bulk.inc
@@ -12,7 +12,7 @@ include_once DRUPAL_ROOT . '/core/includes/gettext.inc';
  */
 function locale_translate_import_form($form, &$form_state) {
   drupal_static_reset('language_list');
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
 
   // Initialize a language list to the ones available, including English if we
   // are to translate Drupal to English as well.
@@ -127,7 +127,8 @@ function locale_translate_import_form_submit($form, &$form_state) {
  * Builds form to export Gettext translation files.
  */
 function locale_translate_export_form($form, &$form_state) {
-  $languages = language_list(TRUE);
+  // Get all configurable languages, except English, if we should not translate that.
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   $language_options = array();
   foreach ($languages as $langcode => $language) {
     if ($langcode != 'en' || locale_translate_english()) {
@@ -242,8 +243,8 @@ function locale_translate_batch_import_files($langcode = NULL, $finish_feedback
   }
   else {
     // If langcode was not provided, make sure to only import files for the
-    // languages we have enabled.
-    $langcodes = array_keys(language_list());
+    // languages we have configured.
+    $langcodes = array_keys(language_list(LANGUAGE_ADD_DISABLED));
   }
   foreach ($langcodes as $langcode) {
     $files = array_merge($files, file_scan_directory($directory, '!' . (!empty($langcode) ? '\.' . preg_quote($langcode, '!') : '') . '\.po$!', array('recurse' => FALSE)));
diff --git a/core/modules/locale/locale.module b/core/modules/locale/locale.module
index 6f81480..655faec 100644
--- a/core/modules/locale/locale.module
+++ b/core/modules/locale/locale.module
@@ -228,15 +228,14 @@ function locale_permission() {
  */
 function locale_language_selector_form($user) {
   global $language_interface;
-  // Get list of enabled languages only.
-  $languages = language_list(TRUE);
+  $languages = language_list();
 
   // If the user is being created, we set the user language to the page language.
   $user_preferred_language = $user->uid ? user_preferred_language($user) : $language_interface;
 
   $names = array();
-  foreach ($languages as $langcode => $item) {
-    $names[$langcode] = $item->name;
+  foreach ($languages as $langcode => $language) {
+    $names[$langcode] = $language->name;
   }
   // Get language negotiation settings.
   $mode = language_negotiation_method_get_first(LANGUAGE_TYPE_INTERFACE) != LANGUAGE_NEGOTIATION_DEFAULT;
@@ -770,7 +769,7 @@ function locale_form_language_admin_overview_form_alter(&$form, &$form_state) {
       'translated' => 0,
       'ratio' => 0,
     );
-    if ($langcode != 'en' || locale_translate_english()) {
+    if (empty($language->locked) && ($langcode != 'en' || locale_translate_english())) {
       $form['languages'][$langcode]['locale_statistics'] = array(
         '#type' => 'link',
         '#title' => t('@translated/@total (@ratio%)', array(
@@ -781,9 +780,14 @@ function locale_form_language_admin_overview_form_alter(&$form, &$form_state) {
         '#href' => 'admin/config/regional/translate/translate',
       );
     }
+    elseif ($langcode == LANGUAGE_SYSTEM) {
+      $form['languages'][$langcode]['locale_statistics'] = array(
+        '#markup' => t('Built-in'),
+      );
+    }
     else {
       $form['languages'][$langcode]['locale_statistics'] = array(
-        '#markup' => t('not applicable'),
+        '#markup' => t('Not applicable'),
       );
     }
   }
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index 74603a9..943c55e 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -28,7 +28,7 @@ function _locale_translate_seek() {
   if (!($query = _locale_translate_seek_query())) {
     $query = array(
       'translation' => 'all',
-      'language' => 'all',
+      'language' => LANGUAGE_ALL,
       'customized' => 'all',
       'string' => '',
     );
@@ -68,7 +68,7 @@ function _locale_translate_seek() {
   }
 
   $limit_language = NULL;
-  if ($query['language'] != LANGUAGE_SYSTEM && $query['language'] != 'all') {
+  if ($query['language'] != LANGUAGE_SYSTEM && $query['language'] != LANGUAGE_ALL) {
     $sql_query->condition('language', $query['language']);
     $limit_language = $query['language'];
   }
@@ -117,7 +117,7 @@ function _locale_translate_language_list($translation, $limit_language) {
   // Add CSS.
   drupal_add_css(drupal_get_path('module', 'locale') . '/locale.css');
 
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   if (!locale_translate_english()) {
     unset($languages['en']);
   }
@@ -154,9 +154,9 @@ function _locale_translate_seek_query() {
 function locale_translation_filters() {
   $filters = array();
 
-  // Get all languages, except English
+  // Get all configurable languages, except English if not translatable.
   drupal_static_reset('language_list');
-  $languages = language_list(TRUE);
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   $language_options = array();
   foreach ($languages as $langcode => $language) {
     if ($langcode != 'en' || locale_translate_english()) {
@@ -171,7 +171,7 @@ function locale_translation_filters() {
 
   $filters['language'] = array(
     'title' => t('Language'),
-    'options' => array_merge(array('all' => t('All languages'), LANGUAGE_SYSTEM => t('System (English)')), $language_options),
+    'options' => array_merge(array(LANGUAGE_ALL => t('All languages'), LANGUAGE_SYSTEM => t('System (English)')), $language_options),
   );
 
   $filters['translation'] = array(
@@ -352,10 +352,11 @@ function locale_translate_edit_form($form, &$form_state, $lid) {
 
   // Include default form controls with empty values for all languages.
   // This ensures that the languages are always in the same order in forms.
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
   if (!locale_translate_english()) {
     unset($languages['en']);
   }
+
   // Store languages to iterate for validation and submission of the form.
   $form_state['langcodes'] = array_keys($languages);
   $plural_formulas = variable_get('locale_translation_plurals', array());
diff --git a/core/modules/locale/locale.test b/core/modules/locale/locale.test
index bb3c6e7..d30d44b 100644
--- a/core/modules/locale/locale.test
+++ b/core/modules/locale/locale.test
@@ -2520,7 +2520,7 @@ class LocaleUILanguageNegotiationTest extends DrupalWebTestCase {
     // is for some reason not found when doing translate search. This might
     // be some bug.
     drupal_static_reset('language_list');
-    $languages = language_list(TRUE);
+    $languages = language_list();
     variable_set('language_default', $languages['vi']);
     // First visit this page to make sure our target string is searchable.
     $this->drupalGet('admin/config');
@@ -2804,7 +2804,7 @@ class LocaleUrlRewritingTest extends DrupalWebTestCase {
    */
   function testUrlRewritingEdgeCases() {
     // Check URL rewriting with a disabled language.
-    $languages = language_list();
+    $languages = language_list(LANGUAGE_ADD_DISABLED);
     $this->checkUrl($languages['it'], t('Path language is ignored if language is disabled.'), t('URL language negotiation does not work with disabled languages'));
 
     // Check URL rewriting with a non-installed language.
diff --git a/core/modules/node/node.admin.inc b/core/modules/node/node.admin.inc
index ac18da7..2d4ec70 100644
--- a/core/modules/node/node.admin.inc
+++ b/core/modules/node/node.admin.inc
@@ -106,10 +106,10 @@ function node_filters() {
 
   // Language filter if language support is present.
   if (language_multilingual()) {
-    $languages = language_list(TRUE);
-    $language_options = array(LANGUAGE_NOT_SPECIFIED => t('- None -'));
+    $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
     foreach ($languages as $langcode => $language) {
-      $language_options[$langcode] = $language->name;
+      // Make locked languages appear special in the list.
+      $language_options[$langcode] = $language->locked ? t('- @name -', array('@name' => $language->name)) : $language->name;
     }
     $filters['language'] = array(
       'title' => t('language'),
@@ -474,7 +474,7 @@ function node_admin_nodes() {
   $nodes = node_load_multiple($nids);
 
   // Prepare the list of nodes.
-  $languages = language_list();
+  $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
   $destination = drupal_get_destination();
   $options = array();
   foreach ($nodes as $node) {
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index a59a5c7..3b668e0 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -2857,8 +2857,9 @@ function node_form_search_form_alter(&$form, $form_state) {
 
     // Languages:
     $language_options = array();
-    foreach (language_list(TRUE) as $langcode => $language) {
-      $language_options[$langcode] = $language->name;
+    foreach (language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED) as $langcode => $language) {
+      // Make locked languages appear special in the list.
+      $language_options[$langcode] = $language->locked ? t('- @name -', array('@name' => $language->name)) : $language->name;
     }
     if (count($language_options) > 1) {
       $form['advanced']['language'] = array(
diff --git a/core/modules/node/node.pages.inc b/core/modules/node/node.pages.inc
index 4e94b26..9389731 100644
--- a/core/modules/node/node.pages.inc
+++ b/core/modules/node/node.pages.inc
@@ -176,17 +176,17 @@ function node_form($form, &$form_state, $node) {
   $form['#node'] = $node;
 
   if (variable_get('node_type_language_' . $node->type, 0) && module_exists('language')) {
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
     $language_options = array();
     foreach ($languages as $langcode => $language) {
-      $language_options[$langcode] = $language->name;
+      // Make locked languages appear special in the list.
+      $language_options[$langcode] = $language->locked ? t('- @name -', array('@name' => $language->name)) : $language->name;
     }
     $form['langcode'] = array(
       '#type' => 'select',
       '#title' => t('Language'),
-      '#default_value' => (isset($node->langcode) ? $node->langcode : ''),
+      '#default_value' => (isset($node->langcode) ? $node->langcode : LANGUAGE_NOT_SPECIFIED),
       '#options' => $language_options,
-      '#empty_value' => LANGUAGE_NOT_SPECIFIED,
     );
   }
   else {
diff --git a/core/modules/openid/openid.module b/core/modules/openid/openid.module
index 141a3ab..2de64a0 100644
--- a/core/modules/openid/openid.module
+++ b/core/modules/openid/openid.module
@@ -263,7 +263,7 @@ function openid_form_user_register_form_alter(&$form, &$form_state) {
         $candidate_langcodes[] = $parts[0] . '-' . $parts[2];
         $candidate_langcodes[] = $parts[0] . '-' . $parts[1] . '-' . $parts[2];
       }
-      $enabled_languages = language_list(TRUE);
+      $enabled_languages = language_list();
       // Iterate over the generated permutations starting with the longest (most
       // specific) strings.
       foreach (array_reverse($candidate_langcodes) as $candidate_langcode) {
diff --git a/core/modules/path/path.admin.inc b/core/modules/path/path.admin.inc
index 24921b8..d6bb7b7 100644
--- a/core/modules/path/path.admin.inc
+++ b/core/modules/path/path.admin.inc
@@ -145,7 +145,7 @@ function path_admin_form($form, &$form_state, $path = array('source' => '', 'ali
 
   // A hidden value unless language.module is enabled.
   if (module_exists('language')) {
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ADD_DISABLED);
     foreach ($languages as $langcode => $language) {
       $language_options[$langcode] = $language->name;
     }
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 6fb56e3..7d0a8a5 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -3909,8 +3909,8 @@ function system_date_format_save($date_format, $dfid = 0) {
     drupal_write_record('date_formats', $info, $keys);
   }
 
-  // Retrieve an array of language objects for enabled languages.
-  $languages = language_list(TRUE);
+  // Retrieve an array of language objects for configurable languages.
+  $languages = language_list(LANGUAGE_ADD_DISABLED);
 
   $locale_format = array();
   $locale_format['type'] = $date_format['type'];
diff --git a/core/modules/system/tests/upgrade/upgrade.language.test b/core/modules/system/tests/upgrade/upgrade.language.test
index e473c63..589632f 100644
--- a/core/modules/system/tests/upgrade/upgrade.language.test
+++ b/core/modules/system/tests/upgrade/upgrade.language.test
@@ -37,7 +37,7 @@ class LanguageUpgradePathTestCase extends UpgradePathTestCase {
 
     // Ensure Catalan was properly upgraded to be the new default language.
     $this->assertTrue(language_default()->langcode == 'ca', t('Catalan is the default language'));
-    $languages = language_list();
+    $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
     foreach ($languages as $language) {
       $this->assertTrue($language->default == ($language->langcode == 'ca'), t('@language default property properly set', array('@language' => $language->name)));
     }
diff --git a/core/modules/translation/translation.module b/core/modules/translation/translation.module
index fa73df5..a36f4cd 100644
--- a/core/modules/translation/translation.module
+++ b/core/modules/translation/translation.module
@@ -137,7 +137,7 @@ function translation_form_node_form_alter(&$form, &$form_state) {
     $node = $form['#node'];
 
     // Build two lists with the disabled and enabled languages.
-    $languages = language_list();
+    $languages = language_list(LANGUAGE_ADD_DISABLED | LANGUAGE_ADD_LOCKED);
     $grouped_languages = array();
     foreach ($languages as $langcode => $language) {
       $grouped_languages[(int) $language->enabled][$langcode] = $language;
@@ -149,7 +149,7 @@ function translation_form_node_form_alter(&$form, &$form_state) {
     // might need to distinguish between enabled and disabled languages, hence
     // we divide them in two option groups.
     if ($translator_widget) {
-      $options = array($groups[1] => array(LANGUAGE_NOT_SPECIFIED => t('- None -')));
+      $options = array();
       foreach (array(1, 0) as $status) {
         $group = $groups[$status];
         foreach ($grouped_languages[$status] as $langcode => $language) {
@@ -223,7 +223,7 @@ function translation_node_view($node, $view_mode) {
   // If the site has no translations or is not multilingual we have no content
   // translation links to display.
   if (isset($node->tnid) && language_multilingual() && $translations = translation_node_get_translations($node->tnid)) {
-    $languages = language_list(TRUE);
+    $languages = language_list(LANGUAGE_ADD_LOCKED);
 
     // There might be a language provider enabled defining custom language
     // switch links which need to be taken into account while generating the
@@ -238,8 +238,7 @@ function translation_node_view($node, $view_mode) {
     foreach ($translations as $langcode => $translation) {
       // Do not show links to the same node, to unpublished translations or to
       // translations in disabled languages.
-      if ($translation->status && isset($languages[$langcode]) && $langcode != $node->langcode) {
-        $language = $languages[$langcode];
+      if ($translation->status && isset($languages[$langcode]) && $languages[$langcode]->enabled && $langcode != $node->langcode) {
         $key = "translation_$langcode";
 
         if (isset($custom_links->links[$langcode])) {
@@ -248,7 +247,7 @@ function translation_node_view($node, $view_mode) {
         else {
           $links[$key] = array(
             'href' => "node/{$translation->nid}",
-            'title' => $language->name,
+            'title' => language_name($langcode),
             'language' => $language,
           );
         }
@@ -295,7 +294,7 @@ function translation_node_prepare($node) {
       return;
     }
 
-    $language_list = language_list();
+    $language_list = language_list(LANGUAGE_ADD_DISABLED);
     $langcode = $_GET['target'];
     if (!isset($language_list[$langcode]) || ($source_node->langcode == $langcode)) {
       // If not supported language, or same language as source node, break.
diff --git a/core/modules/translation/translation.pages.inc b/core/modules/translation/translation.pages.inc
index 66dfc42..4a5c264 100644
--- a/core/modules/translation/translation.pages.inc
+++ b/core/modules/translation/translation.pages.inc
@@ -33,7 +33,7 @@ function translation_node_overview($node) {
   $type = variable_get('translation_language_type', LANGUAGE_TYPE_INTERFACE);
   $header = array(t('Language'), t('Title'), t('Status'), t('Operations'));
 
-  foreach (language_list() as $langcode => $language) {
+  foreach (language_list(LANGUAGE_ADD_DISABLED) as $langcode => $language) {
     $options = array();
     $language_name = $language->name;
     if (isset($translations[$langcode])) {