diff --git a/core/includes/common.inc b/core/includes/common.inc
index c9913a2..7b1bd52 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -6561,7 +6561,7 @@ function drupal_common_theme() {
       'variables' => array(),
     ),
     'table' => array(
-      'variables' => array('header' => NULL, 'rows' => NULL, 'attributes' => array(), 'caption' => NULL, 'colgroups' => array(), 'sticky' => TRUE, 'empty' => ''),
+      'variables' => array('header' => NULL, 'rows' => NULL, 'attributes' => array(), 'caption' => NULL, 'colgroups' => array(), 'sticky' => TRUE, 'responsive' => TRUE, 'empty' => ''),
     ),
     'meter' => array(
       'variables' => array('display_value' => NULL, 'form' => NULL, 'high' => NULL, 'low' => NULL, 'max' => NULL, 'min' => NULL, 'optimum' => NULL, 'value' => NULL, 'percentage' => NULL, 'attributes' => array()),
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 2d1d375..ad5863d 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -34,6 +34,16 @@ const MARK_NEW = 1;
 const MARK_UPDATED = 2;
 
 /**
+ * A responsive table class.
+ */
+const RWD_ADVISABLE = 'advisable';
+
+/**
+ * A responsive table class.
+ */
+const RWD_HELPFUL = 'helpful';
+
+/**
  * @} End of "defgroup content_flags".
  */
 
@@ -1759,6 +1769,9 @@ function theme_breadcrumb($variables) {
  *     - "field": The database field represented in the table column (required
  *       if user is to be able to sort on this column).
  *     - "sort": A default sort order for this column ("asc" or "desc").
+ *     - "class": An array of values for 'class' attribute. In particular,
+ *        less important columns should have 'adviseable' or 'helpful' values.
+ *        Themes may hide less important columns for narrow viewports.
  *     - Any HTML attributes, such as "colspan", to apply to the column header
  *       cell.
  *   - rows: An array of table rows. Every row is an array of cells, or an
@@ -1829,6 +1842,7 @@ function theme_table($variables) {
   $caption = $variables['caption'];
   $colgroups = $variables['colgroups'];
   $sticky = $variables['sticky'];
+  $responsive = $variables['responsive'];
   $empty = $variables['empty'];
 
   // Add sticky headers, if applicable.
@@ -1838,6 +1852,13 @@ function theme_table($variables) {
     // This is needed to target tables constructed by this function.
     $attributes['class'][] = 'sticky-enabled';
   }
+  // If columns are hidden, add a link to show the columns.
+  if (count($header) && $responsive) {
+    drupal_add_library('system', 'drupal.tableresponsive');
+    // Add 'responsive-enabled' class to the table to identify it for JS.
+    // This is needed to target tables constructed by this function.
+    $attributes['class'][] = 'responsive-enabled';
+  }
 
   $output = '<table' . new Attribute($attributes) . ">\n";
 
@@ -1894,16 +1915,31 @@ function theme_table($variables) {
     $rows[] = array(array('data' => $empty, 'colspan' => $header_count, 'class' => array('empty', 'message')));
   }
 
+  $responsive = array();
   // Format the table header:
   if (count($header)) {
     $ts = tablesort_init($header);
     // HTML requires that the thead tag has tr tags in it followed by tbody
     // tags. Using ternary operator to check and see if we have any rows.
     $output .= (count($rows) ? ' <thead><tr>' : ' <tr>');
+    $i=0;
     foreach ($header as $cell) {
+      $i++;
+
+      // Track responsive classes for each column as needed.
+      if (!empty($cell['class']) && is_array($cell['class'])) {
+        if (in_array(RWD_ADVISABLE, $cell['class'])) {
+          $responsive[$i] =  RWD_ADVISABLE;
+        }
+        elseif (in_array(RWD_HELPFUL, $cell['class'])) {
+          $responsive[$i] =  RWD_HELPFUL;
+        }
+      }
+
       $cell = tablesort_header($cell, $header, $ts);
       $output .= _theme_table_cell($cell, TRUE);
     }
+
     // Using ternary operator to close the tags based on whether or not there are rows
     $output .= (count($rows) ? " </tr></thead>\n" : "</tr>\n");
   }
@@ -1944,7 +1980,20 @@ function theme_table($variables) {
         $output .= ' <tr' . new Attribute($attributes) . '>';
         $i = 0;
         foreach ($cells as $cell) {
-          $cell = tablesort_cell($cell, $header, $ts, $i++);
+          $i++;
+          // Add active class if needed for sortable tables.
+          $cell = tablesort_cell($cell, $header, $ts, $i);
+
+          // Copy advisable/helpful class from header to cell as needed.
+          if (isset($responsive[$i])) {
+            if (is_array($cell)) {
+              $cell['class'][] = $responsive[$i];
+            }
+            else {
+              $cell = array('data' => $cell, 'class' => $responsive[$i]);
+            }
+          }
+
           $output .= _theme_table_cell($cell);
         }
         $output .= " </tr>\n";
diff --git a/core/misc/tabledrag.js b/core/misc/tabledrag.js
index 07c50d5..2cd9c7a 100644
--- a/core/misc/tabledrag.js
+++ b/core/misc/tabledrag.js
@@ -50,7 +50,7 @@ Drupal.tableDrag = function (table, tableSettings) {
   var $table = $(table);
 
   // Required object variables.
-  this.table = table;
+  this.$table = $(table);
   this.tableSettings = tableSettings;
   this.dragObject = null; // Used to hold information about a current drag operation.
   this.rowObject = null; // Provides operations for row manipulation.
@@ -58,7 +58,9 @@ Drupal.tableDrag = function (table, tableSettings) {
   this.oldY = 0; // Used to determine up or down direction from last mouse move.
   this.changed = false; // Whether anything in the entire table has changed.
   this.maxDepth = 0; // Maximum amount of allowed parenting.
-  this.rtl = $(this.table).css('direction') === 'rtl' ? -1 : 1; // Direction of the table.
+  this.rtl = this.$table.css('direction') === 'rtl' ? -1 : 1; // Direction of the table.
+  this.showText = Drupal.t('Show row weights');
+  this.hideText = Drupal.t('Hide row weights');
 
   // Configure the scroll settings.
   this.scrollSettings = { amount: 4, interval: 50, trigger: 70 };
@@ -143,7 +145,8 @@ Drupal.tableDrag = function (table, tableSettings) {
  * 'Drupal.tableDrag.showWeight' localStorage value.
  */
 Drupal.tableDrag.prototype.initColumns = function () {
-  var $table = $(this.table), hidden, cell, columnIndex;
+  var $table = this.$table;
+  var hidden, cell, columnIndex;
   for (var group in this.tableSettings) {
     if (this.tableSettings.hasOwnProperty(group)) { // Find the first field in this group.
       for (var d in this.tableSettings[group]) {
@@ -250,7 +253,7 @@ Drupal.tableDrag.prototype.hideColumns = function () {
     this.colSpan = this.colSpan - 1;
   });
   // Change link text.
-  $('.tabledrag-toggle-weight').text(Drupal.t('Show row weights'));
+  $('.tabledrag-toggle-weight').text(this.showText);
 };
 
 /**
@@ -268,7 +271,7 @@ Drupal.tableDrag.prototype.showColumns = function () {
     this.colSpan = this.colSpan + 1;
   });
   // Change link text.
-  $('.tabledrag-toggle-weight').text(Drupal.t('Hide row weights'));
+  $('.tabledrag-toggle-weight').text(this.hideText);
 };
 
 /**
@@ -792,7 +795,7 @@ Drupal.tableDrag.prototype.updateField = function (changedRow, group) {
       // Use the first row in the table as source, because it's guaranteed to
       // be at the root level. Find the first item, then compare this row
       // against it as a sibling.
-      sourceRow = $(this.table).find('tr.draggable:first').get(0);
+      sourceRow = this.$table.find('tr.draggable:first').get(0);
       if (sourceRow === this.rowObject.element) {
         sourceRow = $(this.rowObject.group[this.rowObject.group.length - 1]).next('tr.draggable').get(0);
       }
@@ -914,7 +917,7 @@ Drupal.tableDrag.prototype.restripeTable = function () {
   // :even and :odd are reversed because jQuery counts from 0 and
   // we count from 1, so we're out of sync.
   // Match immediate children of the parent element to allow nesting.
-  $(this.table).find('> tbody > tr.draggable:visible, > tr.draggable:visible')
+  this.$table.find('> tbody > tr.draggable:visible, > tr.draggable:visible')
     .removeClass('odd even')
     .filter(':odd').addClass('even').end()
     .filter(':even').addClass('odd');
diff --git a/core/misc/tableresponsive.js b/core/misc/tableresponsive.js
index 3d1fbac..dd08929 100644
--- a/core/misc/tableresponsive.js
+++ b/core/misc/tableresponsive.js
@@ -7,100 +7,95 @@
 
 "use strict";
 
-  /**
-   * Attach the tableResponsive function to Drupal.behaviors.
-   */
-  Drupal.behaviors.tableResponsive = {
-    attach: function (context, settings) {
-      $(context).find('table.responsive-enabled').once('tableresponsive', function () {
-        $(this).data("drupal-tableresponsive", new Drupal.tableResponsive(this));
-      });
+/**
+ * Attach the tableResponsive function to Drupal.behaviors.
+ */
+Drupal.behaviors.tableResponsive = {
+  attach: function (context, settings) {
+    var $tables = $(context).find('table.responsive-enabled').once('tableresponsive');
+    if ($tables.length) {
+      for (var i = 0, il = $tables.length; i < il; i++) {
+        TableResponsive.tables.push(new TableResponsive($tables[i]));
+      }
     }
-  };
-  /**
-   * A responsive table hides columns at small screen sizes, leaving the most
-   * important columns visible to the end user. Users should not be prevented from
-   * accessing all columns, however. This class adds a toggle to a table with
-   * hidden columns that exposes the columns. Exposing the columns will likely
-   * break layouts, but it provides the user with a means to access data, which
-   * is a guiding principle of responsive design.
-   */
-  Drupal.tableResponsive = function (table) {
-    var self = this;
-    this.$table = $(table);
-    this.table = this.$table.data('drupal-table');
-    this.showText = Drupal.t('Show all columns');
-    this.hideText = Drupal.t('Hide unimportant columns');
-    // Store a reference to the header elements of the table so that the DOM is
-    // traversed only once to find them.
-    this.$headers = this.$table.find('th');
-    // Build a link that will toggle the column visibility.
-    this.actionLink = {
-      'text': this.showText,
-      'attributes': {
-        'title': Drupal.t('Expose table cells that were hidden to make the table fit within a small screen.'),
-        'class': 'responsive-table-toggle',
-        'aria-disabled': 'false'
-      },
-      'namespace': 'drupal-tableresponsive',
-      'callback': $.proxy(this, 'eventhandlerToggleColumns')
-    };
-    // Add the toggle to the table's control bar.
-    this.$columnToggle = this.table.addAction([this.actionLink]);
-    this.$columnToggle.data('drupal-tableresponsive', {});
-    // Attach a resize handler to the window.
-    $(window)
-      .bind('resize.drupal-tableresponsive', Drupal.debounce($.proxy(this, 'eventhandlerEvaluateColumnVisibility'), 250))
-      .triggerHandler('resize.drupal-tableresponsive');
-  };
+  }
+};
+
+/**
+ * A responsive table hides columns at small screen sizes, leaving the most
+ * important columns visible to the end user. Users should not be prevented from
+ * accessing all columns, however. This class adds a toggle to a table with
+ * hidden columns that exposes the columns. Exposing the columns will likely
+ * break layouts, but it provides the user with a means to access data, which
+ * is a guiding principle of responsive design.
+ */
+function TableResponsive (table) {
+  this.$table = $(table);
+  this.table = this.$table.data('drupal-table');
+  this.showText = Drupal.t('Show all columns');
+  this.hideText = Drupal.t('Hide unimportant columns');
+  // Store a reference to the header elements of the table so that the DOM is
+  // traversed only once to find them.
+  this.$headers = this.$table.find('th');
+  // Build a link that will toggle the column visibility.
+
+  // Add a link before the table for users to show or hide weight columns.
+  this.$link = $('<a href="#" class="responsive-table-toggle"></a>')
+    .attr({
+      title: Drupal.t('Expose table cells that were hidden to make the table fit within a small screen.'),
+      'aria-disabled': 'false'
+    })
+    .on('click', $.proxy(this, 'eventhandlerToggleColumns'));
+
+  this.$table.before($('<div class="responsive-table-toggle-columns"></div>').append(this.$link));
+
+  // Attach a resize handler to the window.
+  $(window)
+    .on('resize.drupal-tableresponsive', $.proxy(this, 'eventhandlerEvaluateColumnVisibility'))
+    .trigger('resize.drupal-tableresponsive');
+}
+
+$.extend(TableResponsive, {
+  tables: []
+});
+
   /**
    * Associates an action link with the table that will show hidden columns.
    * Columns are assumed to be hidden if their header's display property is none
    * or if the visibility property is hidden.
    */
-  Drupal.tableResponsive.prototype.eventhandlerEvaluateColumnVisibility = function (event) {
-    var self = this;
-    var $headers = this.$headers;
-    var $toggle = this.$columnToggle;
-    var $hiddenHeaders = $headers.filter('.advisable:hidden, .helpful:hidden');
-    var hiddenLength = $hiddenHeaders.length;
-    var toggleData = $toggle.data('drupal-tableresponsive');
+$.extend(TableResponsive.prototype, {
+  eventhandlerEvaluateColumnVisibility: function (e) {
+    var sticky = +this.$link.attr('data-sticky');
+    var hiddenLength = this.$headers.filter('.advisable:hidden, .helpful:hidden').length;
     // If the table has hidden columns, associate an action link with the table
     // to show the columns.
     if (hiddenLength > 0) {
-      $toggle
-      .show()
-      .attr('aria-disabled', 'false');
-
+      this.$link.show().text(this.showText).attr('aria-disabled', 'false');
     }
     // When the toggle is sticky, its presence is maintained because the user has
     // interacted with it. This is necessary to keep the link visible if the user
     // adjusts screen size and changes the visibilty of columns.
-    if ((!('sticky' in toggleData) && hiddenLength === 0) || ('sticky' in toggleData && !toggleData.sticky && hiddenLength === 0)) {
-      $toggle
-      .hide()
-      .attr('aria-disabled', 'true');
-      delete this.$columnToggle.data('drupal-tableresponsive').sticky;
+    if (!sticky && hiddenLength === 0) {
+      this.$link.hide().text(this.hideText).attr('aria-disabled', 'true');
     }
-  };
+  },
   /**
    * Reveal hidden columns and hide any columns that were revealed because they were
    * previously hidden.
    */
-  Drupal.tableResponsive.prototype.eventhandlerToggleColumns = function (event) {
-    event.preventDefault();
+  eventhandlerToggleColumns: function (e) {
+    e.preventDefault();
     var self = this;
-    var $headers = this.$headers;
     var $hiddenHeaders = this.$headers.filter('.advisable:hidden, .helpful:hidden');
     this.$revealedCells = this.$revealedCells || $();
     // Reveal hidden columns.
     if ($hiddenHeaders.length > 0) {
       $hiddenHeaders.each(function (index, element) {
         var $header = $(this);
-        var position = Number($header.prevAll('th').length);
-        $('tbody tr', this.$table).each(function (index, element) {
-          var $row = $(this);
-          var $cells = $row.find('td:eq(' + position + ')');
+        var position = $header.prevAll('th').length;
+        self.$table.find('tbody tr').each(function () {
+          var $cells = $(this).find('td:eq(' + position + ')');
           $cells.show();
           // Keep track of the revealed cells, so they can be hidden later.
           self.$revealedCells = $().add(self.$revealedCells).add($cells);
@@ -108,21 +103,16 @@
         $header.show();
         // Keep track of the revealed headers, so they can be hidden later.
         self.$revealedCells = $().add(self.$revealedCells).add($header);
-
-
       });
-      this.$columnToggle.text(this.hideText);
-      this.$columnToggle.data('drupal-tableresponsive').sticky = true;
+      this.$link.text(this.hideText).attr('data-sticky', 1);
     }
     // Hide revealed columns.
     else {
       this.$revealedCells.hide();
-      this.$columnToggle.text(this.showText);
       // Strip out display
       this.$revealedCells.each(function (index, element) {
         var $cell = $(this);
-        var style = $cell.attr('style');
-        var properties = style.split(';');
+        var properties = $cell.attr('style').split(';');
         var newProps = [];
         // The columns should simply have the display table-cell property
         // removed, which the jQuery hide method does. The hide method
@@ -132,7 +122,7 @@
         // value from the style attribute.
         var match =  /^display\s*\:\s*none$/;
         for (var i = 0; i < properties.length; i++) {
-          var prop = properties[i]
+          var prop = properties[i];
           prop.trim();
           // Find the display:none property and remove it.
           var isDisplayNone = match.exec(prop);
@@ -144,11 +134,13 @@
         // Return the rest of the style attribute values to the element.
         $cell.attr('style', newProps.join(';'));
       });
-      delete this.$revealedCells;
-      this.$columnToggle.data('drupal-tableresponsive').sticky = false;
+      this.$link.text(this.showText).attr('data-sticky', 0);
       // Refresh the toggle link.
-      $(window)
-      .triggerHandler('resize.drupal-tableresponsive');
+      $(window).trigger('resize.drupal-tableresponsive');
     }
-  };
+  }
+});
+
+Drupal.TableResponsive = TableResponsive;
+
 })(jQuery);
diff --git a/core/modules/comment/comment.admin.inc b/core/modules/comment/comment.admin.inc
index 6210cc5..5737ea4 100644
--- a/core/modules/comment/comment.admin.inc
+++ b/core/modules/comment/comment.admin.inc
@@ -73,9 +73,9 @@ function comment_admin_overview($form, &$form_state, $arg) {
   $status = ($arg == 'approval') ? COMMENT_NOT_PUBLISHED : COMMENT_PUBLISHED;
   $header = array(
     'subject' => array('data' => t('Subject'), 'field' => 'subject'),
-    'author' => array('data' => t('Author'), 'field' => 'name'),
-    'posted_in' => array('data' => t('Posted in'), 'field' => 'node_title'),
-    'changed' => array('data' => t('Updated'), 'field' => 'c.changed', 'sort' => 'desc'),
+    'author' => array('data' => t('Author'), 'field' => 'name', 'class' => array(RWD_ADVISABLE)),
+    'posted_in' => array('data' => t('Posted in'), 'field' => 'node_title', 'class' => array(RWD_HELPFUL)),
+    'changed' => array('data' => t('Updated'), 'field' => 'c.changed', 'sort' => 'desc', 'class' => array(RWD_HELPFUL)),
     'operations' => array('data' => t('Operations')),
   );
 
diff --git a/core/modules/dblog/dblog.admin.inc b/core/modules/dblog/dblog.admin.inc
index 15f2354..3e56751 100644
--- a/core/modules/dblog/dblog.admin.inc
+++ b/core/modules/dblog/dblog.admin.inc
@@ -33,11 +33,11 @@ function dblog_overview() {
 
   $header = array(
     '', // Icon column.
-    array('data' => t('Type'), 'field' => 'w.type'),
-    array('data' => t('Date'), 'field' => 'w.wid', 'sort' => 'desc'),
+    array('data' => t('Type'), 'field' => 'w.type', 'class' => array(RWD_ADVISABLE)),
+    array('data' => t('Date'), 'field' => 'w.wid', 'sort' => 'desc', 'class' => array(RWD_HELPFUL)),
     t('Message'),
-    array('data' => t('User'), 'field' => 'u.name'),
-    array('data' => t('Operations')),
+    array('data' => t('User'), 'field' => 'u.name', 'class' => array(RWD_ADVISABLE)),
+    array('data' => t('Operations'), 'class' => array(RWD_HELPFUL)),
   );
 
   $query = db_select('watchdog', 'w')
diff --git a/core/modules/field_ui/field_ui.admin.inc b/core/modules/field_ui/field_ui.admin.inc
index 29d586e..0b67da6 100644
--- a/core/modules/field_ui/field_ui.admin.inc
+++ b/core/modules/field_ui/field_ui.admin.inc
@@ -17,7 +17,11 @@ function field_ui_fields_list() {
 
   $modules = system_rebuild_module_data();
 
-  $header = array(t('Field name'), t('Field type'), t('Used in'));
+  $header = array(
+    t('Field name'),
+    array('data' => t('Field type'), 'class' => array(RWD_ADVISABLE)),
+    t('Used in'),
+  );
   $rows = array();
   foreach ($instances as $entity_type => $type_bundles) {
     foreach ($type_bundles as $bundle => $bundle_instances) {
diff --git a/core/modules/node/node.admin.inc b/core/modules/node/node.admin.inc
index 5cbe4ef..5c4a198 100644
--- a/core/modules/node/node.admin.inc
+++ b/core/modules/node/node.admin.inc
@@ -436,14 +436,32 @@ function node_admin_nodes() {
 
   // Build the sortable table header.
   $header = array(
-    'title' => array('data' => t('Title'), 'field' => 'n.title'),
-    'type' => array('data' => t('Content type'), 'field' => 'n.type'),
-    'author' => t('Author'),
-    'status' => array('data' => t('Status'), 'field' => 'n.status'),
-    'changed' => array('data' => t('Updated'), 'field' => 'n.changed', 'sort' => 'desc')
+    'title' => array(
+      'data' => t('Title'),
+      'field' => 'n.title',
+    ),
+    'type' => array(
+      'data' => t('Content type'),
+      'field' => 'n.type',
+      'class' => array(RWD_ADVISABLE),
+    ),
+    'author' => array(
+      'data' => t('Author'),
+      'class' => array(RWD_HELPFUL),
+    ),
+    'status' => array(
+      'data' => t('Status'),
+      'field' => 'n.status',
+    ),
+    'changed' => array(
+      'data' => t('Updated'),
+      'field' => 'n.changed',
+      'sort' => 'desc',
+      'class' => array(RWD_HELPFUL)
+    ,)
   );
   if ($multilingual) {
-    $header['language_name'] = array('data' => t('Language'), 'field' => 'n.langcode');
+    $header['language_name'] = array('data' => t('Language'), 'field' => 'n.langcode', 'class' => array(RWD_HELPFUL));
   }
   $header['operations'] = array('data' => t('Operations'));
 
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index 2bf4343..39d89f3 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -921,8 +921,8 @@ function system_modules($form, $form_state = array()) {
       '#header' => array(
         array('data' => t('Enabled'), 'class' => array('checkbox')),
         t('Name'),
-        t('Version'),
-        t('Description'),
+        array('data' => t('Version'), 'class' => array(RWD_ADVISABLE)),
+        array('data' => t('Description'), 'class' => array(RWD_HELPFUL)),
         array('data' => t('Operations'), 'colspan' => 3),
       ),
       // Ensure that the "Core" package fieldset comes first.
diff --git a/core/modules/system/system.base-rtl.css b/core/modules/system/system.base-rtl.css
index d01792e..2d5c63f 100644
--- a/core/modules/system/system.base-rtl.css
+++ b/core/modules/system/system.base-rtl.css
@@ -1,4 +1,3 @@
-
 /**
  * @file
  * Generic theme-independent base styles.
@@ -29,6 +28,13 @@
 }
 
 /**
+ * Table behavior.
+ */
+.table-actions > a {
+  margin-left: 1.5em;
+  margin-right: 0;
+}
+/**
  * TableDrag behavior.
  */
 .draggable a.tabledrag-handle {
diff --git a/core/modules/system/system.base.css b/core/modules/system/system.base.css
index f8a7726..3949103 100644
--- a/core/modules/system/system.base.css
+++ b/core/modules/system/system.base.css
@@ -1,4 +1,3 @@
-
 /**
  * @file
  * Generic theme-independent base styles.
@@ -136,8 +135,18 @@ div.tree-child-horizontal {
   text-align: right; /* LTR */
 }
 
+
+/**
+ * Table behavior.
+ *
+ * @see core/misc/table.js
+ */
+.table-actions > a {
+  margin-right: 1.5em; /* LTR */
+}
+
 /**
- * TableHeader behavior.
+ * Tableheader behavior.
  *
  * @see tableheader.js
  */
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 0ea066b..93cb1dc 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -1297,12 +1297,26 @@ function system_library_info() {
     ),
   );
 
+  // Drupal's tableheader library.
+  $libraries['drupal.tableheader'] = array(
+    'title' => 'Drupal tableheader API',
+    'version' => VERSION,
+    'js' => array(
+      'core/misc/tableheader.js' => array('group' => JS_LIBRARY,),
+    ),
+    'dependencies' => array(
+      array('system', 'jquery'),
+      array('system', 'drupal'),
+      array('system', 'jquery.once'),
+    ),
+  );
+
   // Drupal's tabledrag library.
   $libraries['drupal.tabledrag'] = array(
     'title' => 'Drupal tabledrag',
     'version' => VERSION,
     'js' => array(
-      'core/misc/tabledrag.js' => array('group' => JS_LIBRARY, 'weight' => -1),
+      'core/misc/tabledrag.js' => array('group' => JS_LIBRARY, 'cache' => FALSE),
     ),
     'dependencies' => array(
       array('system', 'jquery'),
@@ -1313,6 +1327,20 @@ function system_library_info() {
     ),
   );
 
+  // Drupal's responsive table API.
+  $libraries['drupal.tableresponsive'] = array(
+    'title' => 'Drupal responsive table API',
+    'version' => VERSION,
+    'js' => array(
+      'core/misc/tableresponsive.js' => array('group' => JS_LIBRARY,),
+    ),
+    'dependencies' => array(
+      array('system', 'jquery'),
+      array('system', 'drupal'),
+      array('system', 'jquery.once'),
+    ),
+  );
+
   // Drupal's collapsible fieldset.
   $libraries['drupal.collapse'] = array(
     'title' => 'Drupal collapsible fieldset',
diff --git a/core/modules/user/user.admin.inc b/core/modules/user/user.admin.inc
index 3c39f24..4ccc806 100644
--- a/core/modules/user/user.admin.inc
+++ b/core/modules/user/user.admin.inc
@@ -145,10 +145,10 @@ function user_admin_account() {
 
   $header = array(
     'username' => array('data' => t('Username'), 'field' => 'u.name'),
-    'status' => array('data' => t('Status'), 'field' => 'u.status'),
-    'roles' => array('data' => t('Roles')),
-    'member_for' => array('data' => t('Member for'), 'field' => 'u.created', 'sort' => 'desc'),
-    'access' => array('data' => t('Last access'), 'field' => 'u.access'),
+    'status' => array('data' => t('Status'), 'field' => 'u.status', 'class' => array(RWD_HELPFUL)),
+    'roles' => array('data' => t('Roles'), 'class' => array(RWD_HELPFUL)),
+    'member_for' => array('data' => t('Member for'), 'field' => 'u.created', 'sort' => 'desc', 'class' => array(RWD_HELPFUL)),
+    'access' => array('data' => t('Last access'), 'field' => 'u.access', 'class' => array(RWD_HELPFUL)),
     'operations' => array('data' => t('Operations')),
   );
 
@@ -1051,4 +1051,3 @@ function user_admin_role_delete_confirm_submit($form, &$form_state) {
   drupal_set_message(t('The role has been deleted.'));
   $form_state['redirect'] = 'admin/people/roles';
 }
-
diff --git a/core/themes/bartik/css/style.css b/core/themes/bartik/css/style.css
index 7532a4a..650ac3a 100644
--- a/core/themes/bartik/css/style.css
+++ b/core/themes/bartik/css/style.css
@@ -1708,3 +1708,20 @@ div.admin-panel .description {
     padding-bottom: 2em;
   }
 }
+
+/**
+ * Responsive tables
+ */
+@media screen and (max-width:28.125em) { /* 450px */
+  th.helpful,
+  td.helpful,
+  th.advisable,
+  td.advisable {
+    display: none;
+  }
+}
+@media screen and (max-width:45em) { /* 720px */
+  th.helpful,
+  td.helpful {
+    display: none;
+  }
diff --git a/core/themes/seven/style-rtl.css b/core/themes/seven/style-rtl.css
index fd9f2ee..7b6240b 100644
--- a/core/themes/seven/style-rtl.css
+++ b/core/themes/seven/style-rtl.css
@@ -1,4 +1,3 @@
-
 /**
  * Generic elements.
  */
@@ -71,10 +70,8 @@ ul.primary {
 /**
  * Page layout.
  */
-#page {
-  padding: 20px 0 40px 0;
-  margin-left: 40px;
-  margin-right: 40px;
+#secondary-links ul.links li {
+  padding: 0 0 10px 10px;
 }
 ul.links li,
 ul.inline li {
diff --git a/core/themes/seven/style.css b/core/themes/seven/style.css
index 86f3fc5..a2e5b5f 100644
--- a/core/themes/seven/style.css
+++ b/core/themes/seven/style.css
@@ -1,4 +1,3 @@
-
 /**
  * Generic elements.
  */
@@ -314,13 +313,43 @@ ul.secondary li.active a.active {
  * Page layout.
  */
 #page {
-  padding: 20px 0 40px 0; /* LTR */
-  margin-right: 40px; /* LTR */
-  margin-left: 40px; /* LTR */
+  padding: 20px 0 40px 0;
+  margin-right: 0.8125em;
+  margin-left: 0.8125em;
   background: #fff;
   position: relative;
   color: #333;
 }
+@media screen and (min-width:28.125em) { /* 450px */
+  #page {
+    margin-left: 1.25em;
+    margin-right: 1.25em;
+  }
+}
+@media screen and (min-width:45em) { /* 720px */
+  #page {
+    margin-left: 2.5em;
+    margin-right: 2.5em;
+  }
+}
+#secondary-links ul.links li {
+  padding: 0 10px 10px 0; /* LTR */
+}
+#secondary-links ul.links li a {
+  font-size: 0.923em;
+  background: #777;
+  color: #fff;
+  text-align: center;
+  padding: 5px;
+  height: 55px;
+  width: 80px;
+  overflow: hidden;
+  -moz-border-radius: 5px;
+  border-radius: 5px;
+}
+#secondary-links ul.links li a:hover {
+  background: #999;
+}
 ul.links li,
 ul.inline li {
   padding-right: 1em; /* LTR */
@@ -474,8 +503,23 @@ table.system-status-report tr.error {
 tr td:last-child {
   border-right: 1px solid #bebfb9; /* LTR */
 }
-
-
+/**
+ * Responsive tables
+ */
+@media screen and (max-width:28.125em) { /* 450px */
+  th.helpful,
+  td.helpful,
+  th.advisable,
+  td.advisable {
+    display: none;
+  }
+}
+@media screen and (max-width:45em) { /* 720px */
+  th.helpful,
+  td.helpful {
+    display: none;
+  }
+}
 /**
  * Fieldsets.
  *
diff --git a/core/themes/stark/css/layout.css b/core/themes/stark/css/layout.css
index a31a774..7055238 100644
--- a/core/themes/stark/css/layout.css
+++ b/core/themes/stark/css/layout.css
@@ -93,3 +93,21 @@ img {
     width: 20%;
   }
 }
+
+/**
+ * Responsive tables
+ */
+@media screen and (max-width:28.125em) { /* 450px */
+  th.helpful,
+  td.helpful,
+  th.advisable,
+  td.advisable {
+    display: none;
+  }
+}
+@media screen and (max-width:45em) { /* 720px */
+  th.helpful,
+  td.helpful {
+    display: none;
+  }
+}