diff --git a/core/includes/config.inc b/core/includes/config.inc
index 8d0eea1..a9e5c8e 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -2,6 +2,7 @@
 
 use Drupal\Core\Config\DatabaseStorage;
 use Drupal\Core\Config\FileStorage;
+use Drupal\Core\Config\FileStorageReadException;
 
 /**
  * @file
@@ -86,3 +87,203 @@ function config_get_storage_names_with_prefix($prefix = '') {
 function config($name, $class = 'Drupal\Core\Config\DrupalConfig') {
   return new $class(new DatabaseStorage($name));
 }
+
+/**
+ * Retrieves metadata for a configuration object or key.
+ *
+ * The configuration name may contain the placeholder '*' which means generic configuration
+ * for all objects of this type. If it doesn't contain it, we load first the generic metadata
+ * and add specific configuration for this type on top of it.
+ *
+ * Example: For image.style.large
+ * 1. Load metadata for image.style.*
+ * 2. Merge metadata for image.style.large
+ *
+ * @param $name
+ *   Configuration name.
+ * @param $key
+ *   Configuration key.
+ */
+function config_meta_data($name, $key = '') {
+  $meta = &drupal_static(__FUNCTION__);
+  if (!isset($meta[$name])) {
+    $meta[$name] = array();
+    // Get first part of name that will determine the module that owns this configuration.
+    $parts = explode('.', $name);
+    $module = $parts[0];
+    // We are looking for a file in $module/meta/$name.yml
+    $module_meta_dir = drupal_get_path('module', $module) . '/meta';
+    if (is_dir($module_meta_dir)) {
+      // If the name doesn't contain '*', start with the generic data
+      $last = array_pop($parts);
+      if ($last != '*') {
+        // Try name ended in * if this one does not exist.
+        $base_name = implode('.', array_merge($parts, array('*')));
+        $meta[$name] = config_meta_data($base_name);
+      }
+      try {
+        $storage = new Filestorage($name);
+        $storage->setPath($module_meta_dir);
+        $meta[$name] = drupal_array_merge_deep($meta[$name], $storage->read());
+      }
+      catch (Drupal\Core\Config\FileStorageReadException $e) {
+        // Either the file does not exist or we cannot decode it.
+        // Do nothing. In the worst case, the value will be an empty array.
+      }
+    }
+  }
+  if ($key) {
+    return isset($meta[$name][$key]) ? $meta[$name][$key] : array();
+  }
+  else {
+    return $meta[$name];
+  }
+}
+
+/**
+ * Build nested configuration properties.
+ */
+function config_meta_build($name, $data) {
+  $meta = config_meta_data($name);
+  $build = _config_meta_match($meta, $data);
+  return $build;
+}
+
+/**
+ * Match configuration metadata against real configuration data.
+ */
+function _config_meta_match($meta, $data, $name = '', $prefix = '', $group = '') {
+  $build = array();
+  foreach ($data as $key => $value) {
+    $index = _config_meta_name($prefix, $key);
+    if (!isset($meta[$index])) {
+      // Default element type when we have no metadata.
+      $build += _config_meta_element(array('type' => 'value'), $value, $name, $key, $group);
+    }
+    elseif (!empty($meta[$index]['subkeys'])) {
+      // First build the base element, then build each element
+      $build += _config_meta_element($meta[$index], NULL, $name, $key, $group);
+      // Nested elements, find subkeys in the file, the current key will be the prefix.
+      $group_name = _config_meta_name($name, $key);
+      $build += _config_meta_match($meta, $value, $group_name, $key, $group_name);
+    }
+    else {
+      $build += _config_meta_element($meta[$index], $value, $name, $key, $group);
+    }
+  }
+  return $build;
+}
+
+/**
+ * Build configuration element with data and metadata.
+ *
+ * @param $base
+ *   Base name for this element.
+ * @param $index
+ *   Index of this element in the data array.
+ */
+function _config_meta_element($meta, $data, $base, $index, $group = '') {
+  $build = array();
+  $name = _config_meta_name($base, $index);
+  if (!empty($meta['nested'])) {
+    $build[$name] = $meta;
+    // Nested elements, fetch metadata for each element using two elements.
+    // - $meta['meta'] will contain the base metadata name.
+    // - $meta['nested'] will contain the property to add to the base metadata name.
+    foreach ($data as $key => $value) {
+      if (isset($value[$meta['nested']])) {
+        $meta_name = $value[$meta['nested']];
+      }
+      else {
+        $meta_name = $meta['meta'];
+      }
+      $element_meta = config_meta_data($meta_name);
+      $build += _config_meta_match($element_meta, $value, _config_meta_name($name, $key), NULL, _config_meta_name($group, $name));
+    }
+  }
+  else {
+    // End element, set data as value.
+    if ($group) {
+      $meta += array('group' => $group);
+    }
+    if (isset($data)) {
+      $meta += array('value' => $data);
+    }
+    $build[$name] = $meta;
+  }
+  //debug($build, "meta match name=$name index=$index");
+  return $build;
+}
+
+/**
+ * Helper function to build metadata name.
+ */
+function _config_meta_name() {
+  $args = func_get_args();
+  return implode('.', array_filter($args));
+}
+
+/**
+ * Build configuration form with metadata and values.
+ */
+function config_form($form, &$form_state, $name) {
+  $data = config($name)->get();
+  $build = config_meta_build($name, $data);
+  // Keep a mapping from config name to array element for nested elements.
+  $mapping = array();
+  foreach ($build as $name => $meta) {
+    if (!empty($meta['type'])) {
+      if (!empty($meta['group'])) {
+        $group = $meta['group'];
+        $mapping[$group][$name] = _config_form_element($meta);
+        $mapping[$name] = &$mapping[$group][$name];
+      }
+      else {
+        $form[$name] = _config_form_element($meta);
+        $mapping[$name] = &$form[$name];
+      }
+    }
+  }
+  return $form;
+}
+
+/**
+ * Create configuration form element.
+ */
+function _config_form_element($meta) {
+  $element = array();
+  foreach ($meta as $key => $value) {
+    switch ($key) {
+      case 'nested':
+      case 'meta':
+      case 'subkeys':
+      case 'group':
+        // Do nothing, these are config only properties.
+        break;
+      case 'value':
+        // Where we set the value will depend on the type of element.
+        switch ($meta['type']) {
+          case 'value':
+            $element['#value'] = $value;
+            break;
+          case 'item':
+            $element['#markup'] = $value;
+            break;
+          default:
+            $element['#default_value'] = $value;
+        }
+
+        break;
+      case 'title':
+      case 'description':
+        // Translatable values.
+        $element['#' . $key] = t($value);
+        break;
+      default:
+        // Other properties just move to form notation.
+        $element['#' . $key] = $value;
+        break;
+    }
+  }
+  return $element;
+}
diff --git a/core/modules/image/config/image.style.large.yml b/core/modules/image/config/image.style.large.yml
index e4f2e1f..df8daa8 100644
--- a/core/modules/image/config/image.style.large.yml
+++ b/core/modules/image/config/image.style.large.yml
@@ -1,7 +1,7 @@
 name: large
 effects:
     image_scale_480_480_1:
-        name: image_scale
+        name: image.style.effects.scale
         data:
             width: '480'
             height: '480'
diff --git a/core/modules/image/config/image.style.medium.yml b/core/modules/image/config/image.style.medium.yml
index 17196b4..b26c71f 100644
--- a/core/modules/image/config/image.style.medium.yml
+++ b/core/modules/image/config/image.style.medium.yml
@@ -1,7 +1,7 @@
 name: medium
 effects:
     image_scale_220_220_1:
-        name: image_scale
+        name: image.style.effects.scale
         data:
             width: '220'
             height: '220'
diff --git a/core/modules/image/config/image.style.thumbnail.yml b/core/modules/image/config/image.style.thumbnail.yml
index 2e6b9c4..c44308d 100644
--- a/core/modules/image/config/image.style.thumbnail.yml
+++ b/core/modules/image/config/image.style.thumbnail.yml
@@ -1,7 +1,7 @@
 name: thumbnail
 effects:
     image_scale_100_100_1:
-        name: image_scale
+        name: image.style.effects.scale
         data:
             width: '100'
             height: '100'
diff --git a/core/modules/image/image.effects.inc b/core/modules/image/image.effects.inc
index 35a6a74..d491796 100644
--- a/core/modules/image/image.effects.inc
+++ b/core/modules/image/image.effects.inc
@@ -10,7 +10,7 @@
  */
 function image_image_effect_info() {
   $effects = array(
-    'image_resize' => array(
+    'image.style.effects.resize' => array(
       'label' => t('Resize'),
       'help' => t('Resizing will make images an exact set of dimensions. This may cause images to be stretched or shrunk disproportionately.'),
       'effect callback' => 'image_resize_effect',
@@ -18,7 +18,7 @@ function image_image_effect_info() {
       'form callback' => 'image_resize_form',
       'summary theme' => 'image_resize_summary',
     ),
-    'image_scale' => array(
+    'image.style.effects.scale' => array(
       'label' => t('Scale'),
       'help' => t('Scaling will maintain the aspect-ratio of the original image. If only a single dimension is specified, the other dimension will be calculated.'),
       'effect callback' => 'image_scale_effect',
@@ -26,7 +26,7 @@ function image_image_effect_info() {
       'form callback' => 'image_scale_form',
       'summary theme' => 'image_scale_summary',
     ),
-    'image_scale_and_crop' => array(
+    'image.style.effects.scale_and_crop' => array(
       'label' => t('Scale and crop'),
       'help' => t('Scale and crop will maintain the aspect-ratio of the original image, then crop the larger dimension. This is most useful for creating perfectly square thumbnails without stretching the image.'),
       'effect callback' => 'image_scale_and_crop_effect',
@@ -34,7 +34,7 @@ function image_image_effect_info() {
       'form callback' => 'image_resize_form',
       'summary theme' => 'image_resize_summary',
     ),
-    'image_crop' => array(
+    'image.style.effects.crop' => array(
       'label' => t('Crop'),
       'help' => t('Cropping will remove portions of an image to make it the specified dimensions.'),
       'effect callback' => 'image_crop_effect',
@@ -42,13 +42,13 @@ function image_image_effect_info() {
       'form callback' => 'image_crop_form',
       'summary theme' => 'image_crop_summary',
     ),
-    'image_desaturate' => array(
+    'image.style.effects.desaturate' => array(
       'label' => t('Desaturate'),
       'help' => t('Desaturate converts an image to grayscale.'),
       'effect callback' => 'image_desaturate_effect',
       'dimensions passthrough' => TRUE,
     ),
-    'image_rotate' => array(
+    'image.style.effects.rotate' => array(
       'label' => t('Rotate'),
       'help' => t('Rotating an image may cause the dimensions of an image to increase to fit the diagonal.'),
       'effect callback' => 'image_rotate_effect',
diff --git a/core/modules/image/meta/image.style.*.yml b/core/modules/image/meta/image.style.*.yml
new file mode 100644
index 0000000..627fe5b
--- /dev/null
+++ b/core/modules/image/meta/image.style.*.yml
@@ -0,0 +1,8 @@
+name:
+  title: 'Machine name'
+  type: 'machine_name'
+effects:
+  title: 'Style effects'
+  type: 'fieldset'
+  nested: 'name'
+  meta: 'image.style.effects.*'
diff --git a/core/modules/image/meta/image.style.effects.*.yml b/core/modules/image/meta/image.style.effects.*.yml
new file mode 100644
index 0000000..672db16
--- /dev/null
+++ b/core/modules/image/meta/image.style.effects.*.yml
@@ -0,0 +1,13 @@
+name:
+  title: 'Style name'
+  type: 'item'
+data:
+  title: 'Data'
+  type: 'fieldset'
+  subkeys: '1'
+weight:
+  title: 'Weight'
+  type: 'weight'
+ieid:
+  title: 'IEID'
+  type: 'ieid'
diff --git a/core/modules/image/meta/image.style.effects.scale.yml b/core/modules/image/meta/image.style.effects.scale.yml
new file mode 100644
index 0000000..f634bc6
--- /dev/null
+++ b/core/modules/image/meta/image.style.effects.scale.yml
@@ -0,0 +1,9 @@
+data.width:
+  title: 'Width'
+  type: 'number'
+data.height:
+  title: 'Height'
+  type: 'number'
+data.upscale:
+  title: 'Upscale'
+  type: 'checkbox'
diff --git a/core/modules/system/meta/system.cron.yml b/core/modules/system/meta/system.cron.yml
new file mode 100644
index 0000000..5e3250e
--- /dev/null
+++ b/core/modules/system/meta/system.cron.yml
@@ -0,0 +1,7 @@
+cron_max_threshold:
+  title: 'Cron max threshold'
+  type: 'integer'
+cron_safe_threshold:
+  title: 'Cron safe threshold'
+  type: 'integer'
+
diff --git a/core/modules/system/meta/system.performance.yml b/core/modules/system/meta/system.performance.yml
new file mode 100644
index 0000000..475041f
--- /dev/null
+++ b/core/modules/system/meta/system.performance.yml
@@ -0,0 +1,15 @@
+cache:
+  title: 'Cache'
+  type: 'boolean'
+page_cache_maximum_age:
+  title: 'Page cache maximum age'
+  type: 'time_interval'
+page_compression:
+  title: 'Page compression'
+  type: 'boolean'
+preprocess_css:
+  title: 'Preprocess CSS'
+  type: 'boolean'
+preprocess_js:
+  title: 'Preprocess Javascript'
+  type: 'boolean'