diff --git misc/instasearch.css misc/instasearch.css
new file mode 100644
index 0000000..eb05476
--- /dev/null
+++ misc/instasearch.css
@@ -0,0 +1,5 @@
+/* $Id$ */
+
+.instasearch-irrelevant {
+  display:none;
+}
\ No newline at end of file
diff --git misc/instasearch.js misc/instasearch.js
new file mode 100644
index 0000000..ee5fb77
--- /dev/null
+++ misc/instasearch.js
@@ -0,0 +1,66 @@
+// $Id$
+
+(function ($) {
+
+Drupal.instasearch = function (container) {
+  var data = { items: undefined, index: undefined };
+
+  var text = function (elem) {
+    var ret = '';
+    if (!$(elem).is('.instasearch-ignore'))
+      for (var i = 0; i < elem.childNodes.length; i++)
+        if (elem.childNodes[i].nodeType != 8)
+          ret += elem.childNodes[i].nodeType != 1 ?
+            elem.childNodes[i].nodeValue :
+            text(elem.childNodes[i]);
+    return ret;
+  };
+
+  var rebuildIndex = function () {
+    data.items = container.find('.instasearch-item');
+    data.index = $.map(data.items, function (elem) {
+      return text(elem).toLowerCase();
+    });
+  };
+
+  container.find('.instasearch-textfield').keyup(function (e) {
+    if (data.index === undefined) {
+      rebuildIndex();
+    }
+
+    var value = $.trim($(this).val().toLowerCase());
+    if (value !== '') {
+      $.each(data.index, function (i, text) {
+        var match = text.indexOf(value) >= 0;
+        data.items.eq(i)
+          [match ? 'addClass' : 'removeClass']('instasearch-match')
+          [match ? 'removeClass' : 'addClass']('instasearch-irrelevant');
+      });
+    }
+    else {
+      data.items.removeClass('instasearch-match').removeClass('instasearch-irrelevant');
+    }
+
+    container.trigger('instasearch');
+  });
+
+  return data;
+};
+
+Drupal.behaviors.instasearch = {
+  attach: function (context) {
+    $('.instasearch-container', context).once('instasearch', function () {
+      var container = $(this);
+      container.data('instasearch', Drupal.instasearch(container));
+    });
+
+    $(context).closest('.instasearch-container').each(function () {
+      var data = $(this).data('instasearch');
+      if (data) {
+        data.index = undefined;
+      }
+    });
+  }
+};
+
+})(jQuery);
\ No newline at end of file
diff --git modules/system/system.admin.inc modules/system/system.admin.inc
index 32edba8..245d595 100644
--- modules/system/system.admin.inc
+++ modules/system/system.admin.inc
@@ -719,6 +719,7 @@ function system_modules($form, $form_state = array()) {
       '#title' => t($package),
       '#collapsible' => TRUE,
       '#theme' => 'system_modules_fieldset',
+      '#attributes' => array('class' => array('instasearch-item')),
       '#header' => array(
         array('data' => t('Enabled'), 'class' => array('checkbox')),
         t('Name'),
@@ -734,6 +735,18 @@ function system_modules($form, $form_state = array()) {
   );
   $form['#action'] = url('admin/config/modules/list/confirm');
 
+  $form['#attributes']['class'] = 'instasearch-container';
+  $form['#attached_js']['misc/instasearch.js'] = array();
+  $form['instasearch'] = array(
+    '#type' => 'markup',
+    '#weight' => -5,
+    '#markup' => '<input type="text" class="instasearch-textfield" />',
+    '#attached' => array(
+      'js' => array('misc/instasearch.js'),
+      'css' => array('misc/instasearch.css'),
+    ),
+  );
+
   return $form;
 }
 
@@ -2166,7 +2179,7 @@ function theme_system_modules_fieldset($form) {
     // If we have help, it becomes the first part
     // of the description - with CSS, it is float: right'd.
     if (isset($module['help'])) {
-      $description = '<div class="module-help">' . drupal_render($module['help']) . '</div>';
+      $description = '<div class="module-help instasearch-ignore">' . drupal_render($module['help']) . '</div>';
     }
     // Add the description, along with any modules it requires.
     $description .= drupal_render($module['description']);
@@ -2177,7 +2190,7 @@ function theme_system_modules_fieldset($form) {
       $description .= '<div class="admin-requirements">' . t('Required by: !module-list', array('!module-list' => implode(', ', $module['#required_by']))) . '</div>';
     }
     $row[] = array('data' => $description, 'class' => array('description'));
-    $rows[] = $row;
+    $rows[] = array('data' => $row, 'class' => array('instasearch-item'));
   }
 
   return theme('table', $form['#header'], $rows);