diff --git a/core/includes/config.inc b/core/includes/config.inc
index 51476b7..f0230c3 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -91,13 +91,13 @@ function config_sync_get_changes(StorageInterface $source_storage, StorageInterf
   foreach (array_intersect($source_names, $target_names) as $name) {
     $source_config_data = $source_storage->read($name);
     $target_config_data = $target_storage->read($name);
-    if ($source_config_data != $target_config_data) {
+    if ($source_config_data !== $target_config_data) {
       $config_changes['change'][] = $name;
     }
   }
 
   // Do not trigger subsequent synchronization operations if there are no
-  // changes in either category.
+  // changes in any category.
   if (empty($config_changes['create']) && empty($config_changes['change']) && empty($config_changes['delete'])) {
     return FALSE;
   }
@@ -129,6 +129,48 @@ function config_sync_changes(array $config_changes, StorageInterface $source_sto
 }
 
 /**
+ * Imports configuration from FileStorage to DatabaseStorage.
+ *
+ * @return bool|null
+ *   TRUE if configuration was imported successfully, FALSE in case of a
+ *   synchronization error, or NULL if there are no changes to synchronize.
+ */
+function config_import() {
+  // Retrieve a list of differences between FileStorage and DatabaseStorage.
+  // @todo Leverage DI + config.storage.info.
+  $source_storage = new FileStorage();
+  $target_storage = new DatabaseStorage();
+
+  $config_changes = config_sync_get_changes($source_storage, $target_storage);
+  if (empty($config_changes)) {
+    return;
+  }
+
+  if (!lock_acquire(__FUNCTION__)) {
+    // Another request is synchronizing configuration.
+    // Return a negative result for UI purposes. We do not differentiate between
+    // an actual synchronization error and a failed lock, because concurrent
+    // synchronizations are an edge-case happening only when multiple developers
+    // or site builders attempt to do it without coordinating.
+    return FALSE;
+  }
+
+  $success = TRUE;
+  try {
+    $remaining_changes = config_import_invoke_owner($config_changes, $source_storage, $target_storage);
+    config_sync_changes($remaining_changes, $source_storage, $target_storage);
+    // Flush all caches and reset static variables after a successful import.
+    drupal_flush_all_caches();
+  }
+  catch (ConfigException $e) {
+    watchdog_exception('config_import', $e);
+    $success = FALSE;
+  }
+  lock_release(__FUNCTION__);
+  return $success;
+}
+
+/**
  * Invokes MODULE_config_import() callbacks for configuration changes.
  *
  * @param array $config_changes
@@ -159,8 +201,18 @@ function config_import_invoke_owner(array $config_changes, StorageInterface $sou
         $old_config
           ->setName($name)
           ->load();
+        // If no data exists in the target storage for the delete operation,
+        // then this change was manually specified and can be skipped.
+        if ($op == 'delete' && $old_config->isNew()) {
+          continue;
+        }
 
         $data = $source_storage->read($name);
+        // If no data exists in the source storage for the create operation,
+        // then this change was manually specified and can be skipped.
+        if ($op == 'create' && $data === FALSE) {
+          continue;
+        }
         $new_config = new Config($storage_dispatcher);
         $new_config->setName($name);
         if ($data !== FALSE) {
@@ -176,3 +228,20 @@ function config_import_invoke_owner(array $config_changes, StorageInterface $sou
   }
   return $config_changes;
 }
+
+/**
+ * Exports configuration from DatabaseStorage to FileStorage.
+ */
+function config_export() {
+  // Retrieve a list of differences between DatabaseStorage and FileStorage.
+  // @todo Leverage DI + config.storage.info.
+  $source_storage = new DatabaseStorage();
+  $target_storage = new FileStorage();
+
+  $config_changes = config_sync_get_changes($source_storage, $target_storage);
+  if (empty($config_changes)) {
+    return;
+  }
+  config_sync_changes($config_changes, $source_storage, $target_storage);
+  return TRUE;
+}
diff --git a/core/includes/form.inc b/core/includes/form.inc
index 395cca7..f5acd24 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -3534,6 +3534,7 @@ function form_process_machine_name($element, &$form_state) {
   // 'source' only) would leave all other properties undefined, if the defaults
   // were defined in hook_element_info(). Therefore, we apply the defaults here.
   $element['#machine_name'] += array(
+    // @todo Use 'label' by default.
     'source' => array('name'),
     'target' => '#' . $element['#id'],
     'label' => t('Machine name'),
diff --git a/core/lib/Drupal/Core/Config/Config.php b/core/lib/Drupal/Core/Config/Config.php
index a749a4b..ea14595 100644
--- a/core/lib/Drupal/Core/Config/Config.php
+++ b/core/lib/Drupal/Core/Config/Config.php
@@ -268,6 +268,7 @@ class Config {
    * Deletes the configuration object.
    */
   public function delete() {
+    // @todo Consider to remove the pruning of data for Config::delete().
     $this->data = array();
     $this->storageDispatcher->selectStorage('write', $this->name)->delete($this->name);
     $this->isNew = TRUE;
diff --git a/core/lib/Drupal/Core/ConfigThingie/ConfigThingieBase.php b/core/lib/Drupal/Core/ConfigThingie/ConfigThingieBase.php
new file mode 100644
index 0000000..3f83cf4
--- /dev/null
+++ b/core/lib/Drupal/Core/ConfigThingie/ConfigThingieBase.php
@@ -0,0 +1,232 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\ConfigThingie\ConfigThingieBase.
+ */
+
+namespace Drupal\Core\ConfigThingie;
+
+use Drupal\Core\Config\Config;
+
+/**
+ * Defines the base configuration thingie.
+ */
+abstract class ConfigThingieBase implements ConfigThingieInterface {
+  /**
+   * The configuration object.
+   *
+   * @var Drupal\Core\Config\Config
+   */
+  protected $config;
+
+  /**
+   * The key of the thingie's ID (machine name).
+   *
+   * @var string
+   */
+  public $idKey = 'id';
+
+  /**
+   * The key of the thingie's label.
+   *
+   * @var string
+   */
+  public $labelKey = 'label';
+
+  /**
+   * The thingie's original ID, if any.
+   *
+   * @var string|null
+   */
+  public $originalID;
+
+  /**
+   * The original configuration object, if any, upon update.
+   *
+   * @var Drupal\Core\ConfigThingie\ConfigThingieInterface
+   */
+  public $original;
+
+  /**
+   * Constructs a new configuration thingie.
+   */
+  public function __construct(Config $config) {
+    $this->setConfig($config);
+  }
+
+  /**
+   * Returns the configuration thingie object's name prefix.
+   *
+   * @return string
+   *   The configuration object name prefix; e.g., for a 'node.type.article'
+   *   thingie, this returns 'node.type'.
+   */
+  abstract public function getConfigPrefix();
+
+  /**
+   * Returns the fully qualified configuration object name for this configuration thingie.
+   *
+   * @return string
+   *   The configuration object name for this configuration thingie. Normally,
+   *   ConfigThingieInterface::getConfigPrefix() and
+   *   ConfigThingieInterface::getID() form the full configuration object name;
+   *   i.e., '[prefix].[id]'.
+   */
+  public function getConfigName() {
+    return $this->getConfigPrefix() . '.' . $this->getID();
+  }
+
+  /**
+   * Returns the basename used for events/hooks for this configuration thingie.
+   *
+   * @return string
+   *   The basename for events/hooks; e.g., for a 'node.type.article' thingie,
+   *   this returns 'node_type'. Normally, this is auto-generated based on
+   *   ConfigThingieInterface::getConfigPrefix().
+   */
+  public function getEventBasename() {
+    return str_replace('.', '_', $this->getConfigPrefix());
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::getID().
+   */
+  public function getID() {
+    return $this->config->get($this->idKey);
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::isNew().
+   */
+  public function isNew() {
+    return $this->config->isNew();
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::getLabel().
+   */
+  public function getLabel() {
+    return $this->config->get($this->labelKey);
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::get().
+   */
+  public function get($property_name) {
+    return $this->config->get($property_name);
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::set().
+   */
+  public function set($property_name, $value) {
+    return $this->config->set($property_name, $value);
+  }
+
+  /**
+   * Sets the configuration object for this configuration thingie.
+   *
+   * @param Drupal\Core\Config\Config $config
+   *   The configuration object containing the data for this configuration
+   *   thingie.
+   *
+   * @return Drupal\Core\ConfigThingie\ConfigThingieInterface
+   *   This configuration thingie (suitable for chained method calls).
+   */
+  public function setConfig(Config $config) {
+    $this->config = $config;
+    // Only set originalID, if the passed in configuration object is stored
+    // already.
+    if (!$this->config->isNew()) {
+      $this->originalID = $this->getID();
+    }
+
+    // Allow modules to react upon load.
+    module_invoke_all($this->getEventBasename() . '_load', $this);
+
+    return $this;
+  }
+
+  /**
+   * Sets the unchanged original of this configuration thingie.
+   *
+   * @param Drupal\Core\Config\Config $config
+   *   The configuration object containing the original data for this
+   *   configuration thingie.
+   *
+   * @return Drupal\Core\ConfigThingie\ConfigThingieInterface
+   *   This configuration thingie (suitable for chained method calls).
+   */
+  public function setOriginal(Config $config) {
+    $this->original = new $this($config);
+    // Ensure that originalID contains the ID of the supplied original
+    // configuration object. setOriginal() may be called from outside of this
+    // class (e.g., hook_config_import()) in order to set a specific original.
+    $this->originalID = $this->original->getID();
+    return $this;
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::save().
+   */
+  public function save() {
+    // Provide the original configuration thingie in $this->original, if any.
+    // originalID is only set, if this configuration thingie already existed
+    // prior to saving.
+    if (isset($this->originalID)) {
+      // Load the original configuration object.
+      // This cannot use ConfigThingieBase::getConfigName(), since that would
+      // yield the name using the current/new ID.
+      $original_config = config($this->getConfigPrefix() . '.' . $this->originalID);
+      // Given the original configuration object, instantiate a new class of the
+      // current class, and provide it in $this->original.
+      $this->setOriginal($original_config);
+    }
+
+    // Ensure that the configuration object name uses the current ID.
+    $this->config->setName($this->getConfigName());
+
+    // Allow modules to react prior to saving.
+    module_invoke_all($this->getEventBasename() . '_presave', $this);
+
+    // Save the configuration object.
+    $this->config->save();
+
+    if (isset($this->originalID)) {
+      // Allow modules to react after inserting new configuration.
+      module_invoke_all($this->getEventBasename() . '_update', $this);
+
+      // Delete the original configuration, if it was renamed.
+      if ($this->originalID !== $this->getID()) {
+        // Configuration data is emptied out upon delete, so back it up and
+        // re-inject it. Delete the old configuration data directly; hooks will
+        // get and will be able to react to the data in $this->original.
+        // @todo Consider to remove the pruning of data for Config::delete().
+        $original_data = $original_config->get();
+        $original_config->delete();
+        $original_config->setData($original_data);
+      }
+    }
+    else {
+      // Allow modules to react after updating existing configuration.
+      module_invoke_all($this->getEventBasename() . '_insert', $this);
+    }
+
+    return $this;
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::delete().
+   */
+  public function delete() {
+    // Allow modules to react prior to deleting the configuration.
+    module_invoke_all($this->getEventBasename() . '_predelete', $this);
+
+    // Delete the configuration object.
+    $this->config->delete();
+
+    // Allow modules to react after deleting the configuration.
+    module_invoke_all($this->getEventBasename() . '_delete', $this);
+  }
+}
diff --git a/core/lib/Drupal/Core/ConfigThingie/ConfigThingieInterface.php b/core/lib/Drupal/Core/ConfigThingie/ConfigThingieInterface.php
new file mode 100644
index 0000000..506ffa2
--- /dev/null
+++ b/core/lib/Drupal/Core/ConfigThingie/ConfigThingieInterface.php
@@ -0,0 +1,91 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\ConfigThingie\ConfigThingieInterface.
+ */
+
+namespace Drupal\Core\ConfigThingie;
+
+/**
+ * Defines the interface common for all configuration thingies.
+ */
+interface ConfigThingieInterface {
+  /**
+   * Returns the ID (machine name) of this configuration thingie.
+   *
+   * @return string
+   *   The ID (machine name) of this configuration thingie. Normally, this is
+   *   the part of the configuration object name after
+   *   ConfigThingieInterface::getConfigPrefix(), and also a property within the
+   *   configuration object.
+   */
+  public function getID();
+
+  /**
+   * Returns whether this configuration thingie is new or have been saved already.
+   *
+   * @return bool
+   *   Whether this configuration thingie is new (TRUE) or has been saved
+   *   already (FALSE).
+   */
+  public function isNew();
+
+  /**
+   * Returns the human-readable label of this configuration thingie.
+   *
+   * @return string
+   *   The label of this configuration thingie.
+   */
+  public function getLabel();
+
+  /**
+   * Returns the router path to the administrative page for this configuration thingie.
+   *
+   * @return string
+   *   The router path of this configuration thingie.
+   *
+   * @todo Check whether this makes sense. Requires access handling and stuff,
+   *   which should probably be harmonized for all configuration thingies, too,
+   *   but... later.
+   */
+  public function getURI();
+
+  /**
+   * Returns the value of a given property from this configuration thingie.
+   *
+   * @param string $property_name
+   *   The name of the property to look up.
+   *
+   * @return mixed|null
+   *   The value of $property_name in the configuration object, or NULL if the
+   *   property is not defined.
+   */
+  public function get($property_name);
+
+  /**
+   * Sets the value of a given property for this configuration thingie.
+   *
+   * @param string $property_name
+   *   The name of the property to set.
+   * @param mixed $value
+   *   The value to set.
+   *
+   * @return Drupal\Core\ConfigThingie\ConfigThingieInterface
+   *   This configuration thingie (suitable for chained method calls).
+   */
+  public function set($property_name, $value);
+
+  /**
+   * Saves this configuration thingie.
+   *
+   * @return Drupal\Core\ConfigThingie\ConfigThingieInterface
+   *   This configuration thingie (suitable for chained method calls).
+   */
+  public function save();
+
+  /**
+   * Deletes this configuration thingie.
+   */
+  public function delete();
+}
diff --git a/core/modules/config/config.admin.inc b/core/modules/config/config.admin.inc
new file mode 100644
index 0000000..87a1463
--- /dev/null
+++ b/core/modules/config/config.admin.inc
@@ -0,0 +1,132 @@
+<?php
+
+/**
+ * @file
+ * Admin page callbacks for the config module.
+ */
+
+use Drupal\Core\Config\DatabaseStorage;
+use Drupal\Core\Config\FileStorage;
+use Drupal\Core\Config\StorageInterface;
+
+/**
+ * Helper function to construct the storage changes in a configuration synchronization form.
+ *
+ * @param array $form
+ *   The form structure to add to. Passed by reference.
+ * @param array $form_state
+ *   The current state of the form. Passed by reference.
+ * @param Drupal\Core\Config\StorageInterface $source_storage
+ *   The source storage to retrieve differences from.
+ * @param Drupal\Core\Config\StorageInterface $target_storage
+ *   The target storage to compare differences to.
+ */
+function config_admin_sync_form(array &$form, array &$form_state, StorageInterface $source_storage, StorageInterface $target_storage) {
+  $config_changes = config_sync_get_changes($source_storage, $target_storage);
+  if (empty($config_changes)) {
+    $form['no_changes'] = array(
+      '#markup' => t('There are no configuration changes.'),
+    );
+    return $form;
+  }
+
+  foreach ($config_changes as $config_change_type => $config_files) {
+    if (empty($config_files)) {
+      continue;
+    }
+    $form[$config_change_type] = array(
+      '#type' => 'fieldset',
+      '#title' => $config_change_type . ' (' . count($config_files) . ')',
+      '#collapsible' => TRUE,
+    );
+    $form[$config_change_type]['config_files'] = array(
+      '#theme' => 'table',
+      '#header' => array('Name'),
+    );
+    foreach ($config_files as $config_file) {
+      $form[$config_change_type]['config_files']['#rows'][] = array($config_file);
+    }
+  }
+}
+
+/**
+ * Form constructor for configuration import form.
+ *
+ * @see config_admin_import_form_submit()
+ */
+function config_admin_import_form($form, &$form_state) {
+  // Retrieve a list of differences between FileStorage and DatabaseStorage.
+  // @todo Leverage DI + config.storage.info.
+  $source_storage = new FileStorage();
+  $target_storage = new DatabaseStorage();
+
+  // Prevent users from deleting all configuration.
+  // If the source storage is empty, that signals the unique condition of not
+  // having exported anything at all, and thus no valid storage to compare the
+  // active storage against.
+  // @todo StorageInterface::listAll() can easily yield hundreds or even
+  //   thousands of entries; consider to add a dedicated isEmpty() method for
+  //   storage controllers.
+  $all = $source_storage->listAll();
+  if (empty($all)) {
+    form_set_error('', t('There is no base configuration. <a href="@export-url">Export</a> it first.', array(
+      '@export-url' => url('admin/config/development/sync/export'),
+    )));
+    return $form;
+  }
+
+  config_admin_sync_form($form, $form_state, $source_storage, $target_storage);
+
+  $form['actions'] = array('#type' => 'actions');
+  $form['actions']['submit'] = array(
+    '#type' => 'submit',
+    '#value' => t('Import'),
+  );
+  return $form;
+}
+
+/**
+ * Form submission handler for config_admin_import_form().
+ */
+function config_admin_import_form_submit($form, &$form_state) {
+  if (config_import()) {
+    drupal_set_message(t('The configuration was imported successfully.'));
+  }
+  else {
+    // Another request may be synchronizing configuration already. Wait for it
+    // to complete before returning the error, so already synchronized changes
+    // do not appear again.
+    lock_wait(__FUNCTION__);
+    drupal_set_message(t('The import failed due to an error. Any errors have been logged.'), 'error');
+  }
+}
+
+/**
+ * Form constructor for configuration export form.
+ *
+ * @see config_admin_export_form_submit()
+ */
+function config_admin_export_form($form, &$form_state) {
+  // Retrieve a list of differences between DatabaseStorage and FileStorage.
+  // @todo Leverage DI + config.storage.info.
+  $source_storage = new DatabaseStorage();
+  $target_storage = new FileStorage();
+
+  config_admin_sync_form($form, $form_state, $source_storage, $target_storage);
+
+  $form['actions'] = array('#type' => 'actions');
+  $form['actions']['submit'] = array(
+    '#type' => 'submit',
+    '#value' => t('Export'),
+  );
+  return $form;
+}
+
+/**
+ * Form submission handler for config_admin_export_form().
+ */
+function config_admin_export_form_submit($form, &$form_state) {
+  config_export();
+  drupal_set_message(t('The configuration was exported successfully.'));
+}
+
diff --git a/core/modules/config/config.module b/core/modules/config/config.module
index b3d9bbc..fd38fd2 100644
--- a/core/modules/config/config.module
+++ b/core/modules/config/config.module
@@ -1 +1,46 @@
 <?php
+
+/**
+ * @file
+ * Allows site administrators to modify configuration.
+ */
+
+/**
+ * Implements hook_permission().
+ */
+function config_permission() {
+  $permissions['synchronize configuration'] = array(
+    'title' => t('Synchronize configuration'),
+    'restrict access' => TRUE,
+  );
+  return $permissions;
+}
+
+/**
+ * Implements hook_menu().
+ */
+function config_menu() {
+  $items['admin/config/development/sync'] = array(
+    'title' => 'Synchronize configuration',
+    'description' => 'Synchronize configuration changes.',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('config_admin_import_form'),
+    'access arguments' => array('synchronize configuration'),
+    'file' => 'config.admin.inc',
+  );
+  $items['admin/config/development/sync/import'] = array(
+    'title' => 'Import',
+    'type' => MENU_DEFAULT_LOCAL_TASK,
+    'weight' => -10,
+  );
+  $items['admin/config/development/sync/export'] = array(
+    'title' => 'Export',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('config_admin_export_form'),
+    'access arguments' => array('synchronize configuration'),
+    'file' => 'config.admin.inc',
+    'type' => MENU_LOCAL_TASK,
+  );
+  return $items;
+}
+
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigConfigurableTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigConfigurableTest.php
new file mode 100644
index 0000000..cfb4bcc
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigConfigurableTest.php
@@ -0,0 +1,80 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config\Tests\ConfigConfigurableTest.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests configurable configuration.
+ */
+class ConfigConfigurableTest extends WebTestBase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Configurable configuration',
+      'description' => 'Tests configurable configuration.',
+      'group' => 'Configuration',
+    );
+  }
+
+  function setUp() {
+    parent::setUp(array('config_test'));
+  }
+
+  /**
+   * Tests basic CRUD operations through the UI.
+   */
+  function testCRUD() {
+    // Create a thingie.
+    $id = 'thingie';
+    $edit = array(
+      'id' => $id,
+      'label' => 'Thingie',
+    );
+    $this->drupalPost('admin/structure/config_test/add', $edit, 'Save');
+    $this->assertResponse(200);
+    $this->assertText('Thingie');
+
+    // Update the thingie.
+    $this->assertLinkByHref('admin/structure/config_test/manage/' . $id);
+    $edit = array(
+      'label' => 'Thongie',
+    );
+    $this->drupalPost('admin/structure/config_test/manage/' . $id, $edit, 'Save');
+    $this->assertResponse(200);
+    $this->assertNoText('Thingie');
+    $this->assertText('Thongie');
+
+    // Delete the thingie.
+    $this->assertLinkByHref('admin/structure/config_test/manage/' . $id . '/delete');
+    $this->drupalPost('admin/structure/config_test/manage/' . $id . '/delete', array(), 'Delete');
+    $this->assertResponse(200);
+    $this->assertNoText('Thingie');
+    $this->assertNoText('Thongie');
+
+    // Re-create a thingie.
+    $edit = array(
+      'id' => $id,
+      'label' => 'Thingie',
+    );
+    $this->drupalPost('admin/structure/config_test/add', $edit, 'Save');
+    $this->assertResponse(200);
+    $this->assertText('Thingie');
+
+    // Rename the thingie's ID/machine name.
+    $this->assertLinkByHref('admin/structure/config_test/manage/' . $id);
+    $new_id = 'zingie';
+    $edit = array(
+      'id' => $new_id,
+      'label' => 'Zingie',
+    );
+    $this->drupalPost('admin/structure/config_test/manage/' . $id, $edit, 'Save');
+    $this->assertResponse(200);
+    $this->assertNoText('Thingie');
+    $this->assertText('Zingie');
+  }
+}
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigImportTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigImportTest.php
new file mode 100644
index 0000000..08eb242
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigImportTest.php
@@ -0,0 +1,185 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config\Tests\ConfigImportTest.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\Core\Config\DatabaseStorage;
+use Drupal\Core\Config\FileStorage;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests importing configuration from files into active store.
+ */
+class ConfigImportTest extends WebTestBase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Import configuration',
+      'description' => 'Tests importing configuration from files into active store.',
+      'group' => 'Configuration',
+    );
+  }
+
+  function setUp() {
+    parent::setUp(array('config_test'));
+
+    // Clear out any possibly existing hook invocation records.
+    unset($GLOBALS['hook_config_test_dynamic']);
+  }
+
+  /**
+   * Tests omission of module APIs for bare configuration operations.
+   */
+  function testNoImport() {
+    $dynamic_name = 'config_test.dynamic.default';
+
+    // Verify the default configuration values exist.
+    $config = config($dynamic_name);
+    $this->assertIdentical($config->get('id'), 'default');
+
+    // Verify that a bare config() does not involve module APIs.
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']));
+
+    // Export.
+    config_export();
+
+    // Verify that config_export() does not involve module APIs.
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']));
+  }
+
+  /**
+   * Tests deletion of configuration during import.
+   */
+  function testDeleted() {
+    $name = 'config_test.system';
+    $dynamic_name = 'config_test.dynamic.default';
+
+    // Verify the default configuration values exist.
+    $config = config($name);
+    $this->assertIdentical($config->get('foo'), 'bar');
+    $config = config($dynamic_name);
+    $this->assertIdentical($config->get('id'), 'default');
+
+    // Export.
+    config_export();
+
+    // Delete the configuration objects.
+    $file_storage = new FileStorage();
+    $file_storage->delete($name);
+    $file_storage->delete($dynamic_name);
+
+    // Import.
+    config_import();
+
+    // Verify the values have disappeared.
+    $database_storage = new DatabaseStorage();
+    $this->assertIdentical($database_storage->read($name), FALSE);
+    $this->assertIdentical($database_storage->read($dynamic_name), FALSE);
+
+    $config = config($name);
+    $this->assertIdentical($config->get('foo'), NULL);
+    $config = config($dynamic_name);
+    $this->assertIdentical($config->get('id'), NULL);
+
+    // Verify that appropriate module API hooks have been invoked.
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['load']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['presave']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['insert']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['update']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['predelete']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['delete']));
+  }
+
+  /**
+   * Tests creation of configuration during import.
+   */
+  function testNew() {
+    $name = 'config_test.new';
+    $dynamic_name = 'config_test.dynamic.new';
+
+    // Verify the configuration to create does not exist yet.
+    $file_storage = new FileStorage();
+    $this->assertIdentical($file_storage->exists($name), FALSE, $name . ' not found.');
+    $this->assertIdentical($file_storage->exists($dynamic_name), FALSE, $dynamic_name . ' not found.');
+
+    // Export.
+    config_export();
+
+    // Create new configuration objects.
+    $file_storage->write($name, array(
+      'add_me' => 'new value',
+    ));
+    $file_storage->write($dynamic_name, array(
+      'id' => 'new',
+      'label' => 'New',
+    ));
+    $this->assertIdentical($file_storage->exists($name), TRUE, $name . ' found.');
+    $this->assertIdentical($file_storage->exists($dynamic_name), TRUE, $dynamic_name . ' found.');
+
+    // Import.
+    config_import();
+
+    // Verify the values appeared.
+    $config = config($name);
+    $this->assertIdentical($config->get('add_me'), 'new value');
+    $config = config($dynamic_name);
+    $this->assertIdentical($config->get('label'), 'New');
+
+    // Verify that appropriate module API hooks have been invoked.
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['load']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['presave']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['insert']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['update']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['predelete']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['delete']));
+  }
+
+  /**
+   * Tests updating of configuration during import.
+   */
+  function testUpdated() {
+    $name = 'config_test.system';
+    $dynamic_name = 'config_test.dynamic.default';
+
+    // Export.
+    config_export();
+
+    // Replace the file content of the existing configuration objects.
+    $file_storage = new FileStorage();
+    $this->assertIdentical($file_storage->exists($name), TRUE, $name . ' found.');
+    $this->assertIdentical($file_storage->exists($dynamic_name), TRUE, $dynamic_name . ' found.');
+    $file_storage->write($name, array(
+      'foo' => 'beer',
+    ));
+    $file_storage->write($dynamic_name, array(
+      'id' => 'default',
+      'label' => 'Updated',
+    ));
+
+    // Verify the active store still returns the default values.
+    $config = config($name);
+    $this->assertIdentical($config->get('foo'), 'bar');
+    $config = config($dynamic_name);
+    $this->assertIdentical($config->get('label'), 'Default');
+
+    // Import.
+    config_import();
+
+    // Verify the values were updated.
+    $config = config($name);
+    $this->assertIdentical($config->get('foo'), 'beer');
+    $config = config($dynamic_name);
+    $this->assertIdentical($config->get('label'), 'Updated');
+
+    // Verify that appropriate module API hooks have been invoked.
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['load']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['presave']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['insert']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['update']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['predelete']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['delete']));
+  }
+}
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigImportUITest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigImportUITest.php
new file mode 100644
index 0000000..cdd2704
--- /dev/null
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigImportUITest.php
@@ -0,0 +1,144 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config\Tests\ConfigImportUITest.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\Core\Config\DatabaseStorage;
+use Drupal\Core\Config\FileStorage;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests importing configuration from files into active store.
+ */
+class ConfigImportUITest extends WebTestBase {
+  public static function getInfo() {
+    return array(
+      'name' => 'Import/Export UI',
+      'description' => 'Tests the user interface for importing/exporting configuration.',
+      'group' => 'Configuration',
+    );
+  }
+
+  function setUp() {
+    parent::setUp(array('config', 'config_test'));
+
+    $this->web_user = $this->drupalCreateUser(array('synchronize configuration'));
+    $this->drupalLogin($this->web_user);
+  }
+
+  /**
+   * Tests exporting configuration.
+   */
+  function testExport() {
+    $name = 'config_test.system';
+    $dynamic_name = 'config_test.dynamic.default';
+
+    // Verify the default configuration values exist.
+    $config = config($name);
+    $this->assertIdentical($config->get('foo'), 'bar');
+    $config = config($dynamic_name);
+    $this->assertIdentical($config->get('id'), 'default');
+
+    // Verify that both appear as deleted by default.
+    $this->drupalGet('admin/config/development/sync/export');
+    $this->assertText($name);
+    $this->assertText($dynamic_name);
+
+    // Export and verify that both do not appear anymore.
+    $this->drupalPost(NULL, array(), t('Export'));
+    $this->assertUrl('admin/config/development/sync/export');
+    $this->assertNoText($name);
+    $this->assertNoText($dynamic_name);
+
+    // Verify that there are no further changes to export.
+    $this->assertText(t('There are no configuration changes.'));
+
+    // Verify that the import screen shows no changes either.
+    $this->drupalGet('admin/config/development/sync');
+    $this->assertText(t('There are no configuration changes.'));
+  }
+
+  /**
+   * Tests importing configuration.
+   */
+  function testImport() {
+    $name = 'config_test.new';
+    $dynamic_name = 'config_test.dynamic.new';
+
+    // Verify the configuration to create does not exist yet.
+    $file_storage = new FileStorage();
+    $this->assertIdentical($file_storage->exists($name), FALSE, $name . ' not found.');
+    $this->assertIdentical($file_storage->exists($dynamic_name), FALSE, $dynamic_name . ' not found.');
+
+    // Verify that the import UI does not allow to import without exported
+    // configuration.
+    $this->drupalGet('admin/config/development/sync');
+    $this->assertText('There is no base configuration.');
+
+    // Verify that the Export link yields to the export UI page, and export.
+    $this->clickLink('Export');
+    $this->drupalPost(NULL, array(), t('Export'));
+
+    // Create new configuration objects.
+    $file_storage->write($name, array(
+      'add_me' => 'new value',
+    ));
+    $file_storage->write($dynamic_name, array(
+      'id' => 'new',
+      'label' => 'New',
+    ));
+    $this->assertIdentical($file_storage->exists($name), TRUE, $name . ' found.');
+    $this->assertIdentical($file_storage->exists($dynamic_name), TRUE, $dynamic_name . ' found.');
+
+    // Verify that both appear as new.
+    $this->drupalGet('admin/config/development/sync');
+    $this->assertText($name);
+    $this->assertText($dynamic_name);
+
+    // Import and verify that both do not appear anymore.
+    $this->drupalPost(NULL, array(), t('Import'));
+    $this->assertUrl('admin/config/development/sync');
+    $this->assertNoText($name);
+    $this->assertNoText($dynamic_name);
+
+    // Verify that there are no further changes to import.
+    $this->assertText(t('There are no configuration changes.'));
+
+    // Verify that the export screen shows no changes either.
+    $this->drupalGet('admin/config/development/sync/export');
+    $this->assertText(t('There are no configuration changes.'));
+  }
+
+  /**
+   * Tests concurrent importing of configuration.
+   */
+  function testImportLock() {
+    $name = 'config_test.new';
+
+    // Write a configuration object to import.
+    $file_storage = new FileStorage();
+    $file_storage->write($name, array(
+      'add_me' => 'new value',
+    ));
+
+    // Verify that there are configuration differences to import.
+    $this->drupalGet('admin/config/development/sync');
+    $this->assertNoText(t('There are no configuration changes.'));
+
+    // Acquire a fake-lock on the import mechanism.
+    $lock_name = 'config_import';
+    lock_acquire($lock_name);
+
+    // Attempt to import configuration and verify that an error message appears.
+    $this->drupalPost(NULL, array(), t('Import'));
+    $this->assertUrl('admin/config/development/sync');
+    $this->assertText(t('The import failed due to an error. Any errors have been logged.'));
+
+    // Release the lock, just to keep testing sane.
+    lock_release($lock_name);
+  }
+}
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php
index 7ec6d8e..a9676ef 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigInstallTest.php
@@ -46,5 +46,14 @@ class ConfigInstallTest extends WebTestBase {
     // Verify that configuration import callback was invoked for the dynamic
     // thingie.
     $this->assertTrue($GLOBALS['hook_config_import']);
+
+    // Verify that config_test API hooks were invoked for the dynamic default
+    // thingie.
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['load']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['presave']));
+    $this->assertTrue(isset($GLOBALS['hook_config_test_dynamic']['insert']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['update']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['predelete']));
+    $this->assertFalse(isset($GLOBALS['hook_config_test_dynamic']['delete']));
   }
 }
diff --git a/core/modules/config/tests/config_test/config/config_test.delete.yml b/core/modules/config/tests/config_test/config/config_test.delete.yml
new file mode 100644
index 0000000..b8ccb67
--- /dev/null
+++ b/core/modules/config/tests/config_test/config/config_test.delete.yml
@@ -0,0 +1 @@
+delete_me: bar
diff --git a/core/modules/config/tests/config_test/config_test.hooks.inc b/core/modules/config/tests/config_test/config_test.hooks.inc
new file mode 100644
index 0000000..2ec6831
--- /dev/null
+++ b/core/modules/config/tests/config_test/config_test.hooks.inc
@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * @file
+ * Fake third-party hook implementations for ConfigTest/config_test thingies.
+ *
+ * Testing the module/hook system is not the purpose of this test helper module.
+ * Therefore, this file implements hooks on behalf of config_test module for
+ * config_test thingie hooks themselves.
+ */
+
+/**
+ * Implements hook_config_test_dynamic_load().
+ */
+function config_test_config_test_dynamic_load() {
+  $GLOBALS['hook_config_test_dynamic']['load'] = __FUNCTION__;
+}
+
+/**
+ * Implements hook_config_test_dynamic_presave().
+ */
+function config_test_config_test_dynamic_presave() {
+  $GLOBALS['hook_config_test_dynamic']['presave'] = __FUNCTION__;
+}
+
+/**
+ * Implements hook_config_test_dynamic_insert().
+ */
+function config_test_config_test_dynamic_insert() {
+  $GLOBALS['hook_config_test_dynamic']['insert'] = __FUNCTION__;
+}
+
+/**
+ * Implements hook_config_test_dynamic_update().
+ */
+function config_test_config_test_dynamic_update() {
+  $GLOBALS['hook_config_test_dynamic']['update'] = __FUNCTION__;
+}
+
+/**
+ * Implements hook_config_test_dynamic_predelete().
+ */
+function config_test_config_test_dynamic_predelete() {
+  $GLOBALS['hook_config_test_dynamic']['predelete'] = __FUNCTION__;
+}
+
+/**
+ * Implements hook_config_test_dynamic_delete().
+ */
+function config_test_config_test_dynamic_delete() {
+  $GLOBALS['hook_config_test_dynamic']['delete'] = __FUNCTION__;
+}
diff --git a/core/modules/config/tests/config_test/config_test.module b/core/modules/config/tests/config_test/config_test.module
index 6fd84a2..fe18c4a 100644
--- a/core/modules/config/tests/config_test/config_test.module
+++ b/core/modules/config/tests/config_test/config_test.module
@@ -1,5 +1,9 @@
 <?php
 
+use Drupal\config_test\ConfigTest;
+
+require_once dirname(__FILE__) . '/config_test.hooks.inc';
+
 /**
  * Implements MODULE_config_import_create().
  */
@@ -12,7 +16,8 @@ function config_test_config_import_create($name, $new_config, $old_config) {
   // Set a global value we can check in test code.
   $GLOBALS['hook_config_import'] = __FUNCTION__;
 
-  $new_config->save();
+  $config_test = new ConfigTest($new_config);
+  $config_test->save();
   return TRUE;
 }
 
@@ -28,7 +33,9 @@ function config_test_config_import_change($name, $new_config, $old_config) {
   // Set a global value we can check in test code.
   $GLOBALS['hook_config_import'] = __FUNCTION__;
 
-  $new_config->save();
+  $config_test = new ConfigTest($new_config);
+  $config_test->setOriginal($old_config);
+  $config_test->save();
   return TRUE;
 }
 
@@ -44,7 +51,208 @@ function config_test_config_import_delete($name, $new_config, $old_config) {
   // Set a global value we can check in test code.
   $GLOBALS['hook_config_import'] = __FUNCTION__;
 
-  $old_config->delete();
+  $config_test = new ConfigTest($old_config);
+  $config_test->delete();
   return TRUE;
 }
 
+/**
+ * Implements hook_menu().
+ */
+function config_test_menu() {
+  $items['admin/structure/config_test'] = array(
+    'title' => 'Test configuration',
+    'page callback' => 'config_test_list_page',
+    'access callback' => TRUE,
+  );
+  $items['admin/structure/config_test/add'] = array(
+    'title' => 'Add test configuration',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('config_test_form'),
+    'access callback' => TRUE,
+    'type' => MENU_LOCAL_ACTION,
+  );
+  $items['admin/structure/config_test/manage/%config_test'] = array(
+    'title' => 'Edit test configuration',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('config_test_form', 4),
+    'access callback' => TRUE,
+  );
+  $items['admin/structure/config_test/manage/%config_test/edit'] = array(
+    'title' => 'Edit',
+    'type' => MENU_DEFAULT_LOCAL_TASK,
+    'weight' => -10,
+  );
+  $items['admin/structure/config_test/manage/%config_test/delete'] = array(
+    'title' => 'Delete',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('config_test_delete_form', 4),
+    'access callback' => TRUE,
+    'type' => MENU_LOCAL_TASK,
+  );
+  return $items;
+}
+
+/**
+ * Loads a ConfigTest object.
+ *
+ * @param string $id
+ *   The ID of the ConfigTest object to load.
+ */
+function config_test_load($id) {
+  $config = config('config_test.dynamic.' . $id);
+  if ($config->isNew()) {
+    return FALSE;
+  }
+  return new ConfigTest($config);
+}
+
+/**
+ * Saves a ConfigTest object.
+ *
+ * @param Drupal\config_test\ConfigTest $config_test
+ *   The ConfigTest object to save.
+ */
+function config_test_save(ConfigTest $config_test) {
+  return $config_test->save();
+}
+
+/**
+ * Deletes a ConfigTest object.
+ *
+ * @param string $id
+ *   The ID of the ConfigTest object to delete.
+ */
+function config_test_delete($id) {
+  $config = config('config_test.dynamic.' . $id);
+  $config_test = new ConfigTest($config);
+  return $config_test->delete();
+}
+
+/**
+ * Page callback; Lists available ConfigTest objects.
+ */
+function config_test_list_page() {
+  $config_names = config_get_storage_names_with_prefix('config_test.dynamic.');
+  $rows = array();
+  foreach ($config_names as $config_name) {
+    $config_test = new ConfigTest(config($config_name));
+    $row = array();
+    $row['name']['data'] = array(
+      '#type' => 'link',
+      '#title' => $config_test->getLabel(),
+      '#href' => $config_test->getUri(),
+    );
+    $row['delete']['data'] = array(
+      '#type' => 'link',
+      '#title' => t('Delete'),
+      '#href' => $config_test->getUri() . '/delete',
+    );
+    $rows[] = $row;
+  }
+  $build = array(
+    '#theme' => 'table',
+    '#header' => array('Name', 'Operations'),
+    '#rows' => $rows,
+    '#empty' => format_string('No test configuration defined. <a href="@add-url">Add some</a>', array(
+      '@add-url' => url('admin/structure/config_test/add'),
+    )),
+  );
+  return $build;
+}
+
+/**
+ * Form constructor to add or edit a ConfigTest object.
+ *
+ * @param Drupal\config_test\ConfigTest $config_test
+ *   (optional) An existing ConfigTest object to edit. If omitted, the form
+ *   creates a new ConfigTest.
+ */
+function config_test_form($form, &$form_state, ConfigTest $config_test = NULL) {
+  if (!isset($config_test)) {
+    $config_test = new ConfigTest(config(NULL));
+  }
+  $form_state['config_test'] = $config_test;
+
+  $form['label'] = array(
+    '#type' => 'textfield',
+    '#title' => 'Label',
+    '#default_value' => $config_test->getLabel(),
+    '#required' => TRUE,
+  );
+  $form['id'] = array(
+    '#type' => 'machine_name',
+    '#default_value' => $config_test->getID(),
+    '#required' => TRUE,
+    '#machine_name' => array(
+      'exists' => 'config_test_load',
+      // @todo Update form_process_machine_name() to use 'label' by default.
+      'source' => array('label'),
+    ),
+  );
+  $form['style'] = array(
+    '#type' => 'select',
+    '#title' => 'Image style',
+    '#options' => array(),
+    '#default_value' => $config_test->get('style'),
+    '#access' => FALSE,
+  );
+  if (module_exists('image')) {
+    $form['style']['#access'] = TRUE;
+    $form['style']['#options'] = image_style_options();
+  }
+
+  $form['actions'] = array('#type' => 'actions');
+  $form['actions']['submit'] = array('#type' => 'submit', '#value' => 'Save');
+
+  return $form;
+}
+
+/**
+ * Form submission handler for config_test_form().
+ */
+function config_test_form_submit($form, &$form_state) {
+  form_state_values_clean($form_state);
+
+  $config_test = $form_state['config_test'];
+
+  foreach ($form_state['values'] as $key => $value) {
+    $config_test->set($key, $value);
+  }
+  $config_test->save();
+
+  if (!empty($config_test->original)) {
+    drupal_set_message(format_string('%label configuration has been updated.', array('%label' => $config_test->getLabel())));
+  }
+  else {
+    drupal_set_message(format_string('%label configuration has been created.', array('%label' => $config_test->getLabel())));
+  }
+
+  $form_state['redirect'] = 'admin/structure/config_test';
+}
+
+/**
+ * Form constructor to delete a ConfigTest object.
+ *
+ * @param Drupal\config_test\ConfigTest $config_test
+ *   The ConfigTest object to delete.
+ */
+function config_test_delete_form($form, &$form_state, ConfigTest $config_test) {
+  $form_state['config_test'] = $config_test;
+
+  $form['id'] = array('#type' => 'value', '#value' => $config_test->getID());
+  return confirm_form($form,
+    format_string('Are you sure you want to delete %label', array('%label' => $config_test->getLabel())),
+    'admin/structure/config_test',
+    NULL,
+    'Delete'
+  );
+}
+
+/**
+ * Form submission handler for config_test_delete_form().
+ */
+function config_test_delete_form_submit($form, &$form_state) {
+  $form_state['config_test']->delete();
+  $form_state['redirect'] = 'admin/structure/config_test';
+}
diff --git a/core/modules/config/tests/config_test/lib/Drupal/config_test/ConfigTest.php b/core/modules/config/tests/config_test/lib/Drupal/config_test/ConfigTest.php
new file mode 100644
index 0000000..4efaae5
--- /dev/null
+++ b/core/modules/config/tests/config_test/lib/Drupal/config_test/ConfigTest.php
@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\config_test\ConfigTest.
+ */
+
+namespace Drupal\config_test;
+
+use Drupal\Core\ConfigThingie\ConfigThingieBase;
+
+/**
+ * Defines the ConfigTest configuration thingie.
+ */
+class ConfigTest extends ConfigThingieBase {
+  /**
+   * The image style to use.
+   *
+   * @var string
+   */
+  public $style;
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::getConfigPrefix().
+   */
+  public function getConfigPrefix() {
+    return 'config_test.dynamic';
+  }
+
+  /**
+   * Implements Drupal\Core\ConfigThingie\ConfigThingieInterface::getURI().
+   */
+  public function getURI() {
+    return 'admin/structure/config_test/manage/' . $this->getID();
+  }
+}