diff --git a/core/modules/layout/layout.info b/core/modules/layout/layout.info
index e6e4a66..187bfea 100644
--- a/core/modules/layout/layout.info
+++ b/core/modules/layout/layout.info
@@ -1,5 +1,5 @@
 name = Layout
-description = Provide abstract layout handling for html delivering routes.
+description = Makes it possible to swap different page layouts.
 package = Core
 version = VERSION
 core = 8.x
diff --git a/core/modules/layout/layout.module b/core/modules/layout/layout.module
index 56f223c..cbc0b9d 100644
--- a/core/modules/layout/layout.module
+++ b/core/modules/layout/layout.module
@@ -1,6 +1,11 @@
 <?php
 
 /**
+ * @file
+ * Manages page layouts for content presentation.
+ */
+
+/**
  * Implements hook_page_build().
  */
 function layout_page_build(&$page) {
@@ -10,7 +15,8 @@ function layout_page_build(&$page) {
 /**
  * #pre_render callback for $page.
  *
- * @todo Eventually, Drupal routing will be improved so as to replace
+ * @todo
+ *   Eventually, Drupal routing will be improved so as to replace
  *   drupal_render_page() (which builds blocks from bottom-up, even if the
  *   layout instance is not configured to render them) with a top-down
  *   subrequest workflow. For now, however, we integrate with the
@@ -30,11 +36,23 @@ function layout_page_pre_render($page) {
   return $page;
 }
 
+/**
+ * Get the layout plugin manager instance.
+ *
+ * @return Drupal\layout\Plugin\Type\LayoutManager
+ *   The layout plugin manager instance.
+ */
 function layout_manager() {
   return drupal_container()->get('plugin.manager.layout');
 }
 
-function layout_get_layout(Request $request) {
+/**
+ * Temporary code to make Bartik work.
+ *
+ * @todo
+ *   Make this work generally.
+ */
+function layout_get_layout() {
   global $theme;
   if ($theme == 'bartik') {
     $conf = array(
diff --git a/core/modules/layout/layout/onecol/layout--onecol.tpl.php b/core/modules/layout/layout/onecol/layout--onecol.tpl.php
index 73ad5b8..22cec95 100644
--- a/core/modules/layout/layout/onecol/layout--onecol.tpl.php
+++ b/core/modules/layout/layout/onecol/layout--onecol.tpl.php
@@ -1,15 +1,15 @@
 <?php
 /**
  * @file
- * Template for a 3 column panel layout.
+ * Template for a one column layout.
  *
- * This template provides a very simple "one column" panel display layout.
+ * This template provides a very simple "one column" display layout.
  *
  * Variables:
  * - $id: An optional CSS id to use for the layout.
  * - $content: An array of content, each item in the array is keyed to one
- *   panel of the layout. This layout supports the following sections:
- *   $content['middle']: The only panel in the layout.
+ *   region of the layout. This layout supports the following sections:
+ *   $content['middle']: The only region in the layout.
  */
 ?>
 <div class="panel-display panel-1col clearfix" <?php if (!empty($css_id)) { print "id=\"$css_id\""; } ?>>
diff --git a/core/modules/layout/layout/twocol/layout--twocol.tpl.php b/core/modules/layout/layout/twocol/layout--twocol.tpl.php
index 2cda08e..3ba70d1 100644
--- a/core/modules/layout/layout/twocol/layout--twocol.tpl.php
+++ b/core/modules/layout/layout/twocol/layout--twocol.tpl.php
@@ -1,15 +1,15 @@
 <?php
 /**
  * @file
- * Template for a 2 column panel layout.
+ * Template for a 2 column layout.
  *
- * This template provides a two column panel display layout, with
- * each column roughly equal in width.
+ * This template provides a two column layout, with each column roughly equal
+ * in width.
  *
  * Variables:
  * - $id: An optional CSS id to use for the layout.
  * - $content: An array of content, each item in the array is keyed to one
- *   panel of the layout. This layout supports the following sections:
+ *   region of the layout. This layout supports the following sections:
  *   - $content['left']: Content in the left column.
  *   - $content['right']: Content in the right column.
  */
diff --git a/core/modules/layout/layout/twocol/twocol.css b/core/modules/layout/layout/twocol/twocol.css
index 6e53eca..d85db0f 100644
--- a/core/modules/layout/layout/twocol/twocol.css
+++ b/core/modules/layout/layout/twocol/twocol.css
@@ -1,29 +1,29 @@
 
-.panel-2col { 
+.panel-2col {
 /*  overflow: hidden;  */
 }
 
-.panel-2col .panel-col-first { 
-  float: left; 
-  width: 50%; 
+.panel-2col .panel-col-first {
+  float: left;
+  width: 50%;
 }
 * html .panel-2col .panel-col-first {
   width: 49.9%;
 }
 
-.panel-2col .panel-col-first .inside { 
+.panel-2col .panel-col-first .inside {
   margin: 0 .5em 1em 0;
 }
 
-.panel-2col .panel-col-last { 
-  float: left; 
-  width: 50%; 
+.panel-2col .panel-col-last {
+  float: left;
+  width: 50%;
 }
 * html .panel-2col .panel-col-last {
   width: 49.9%;
 }
 
-.panel-2col .panel-col-last .inside { 
+.panel-2col .panel-col-last .inside {
   margin: 0 0 1em .5em;
 }
 
diff --git a/core/modules/layout/lib/Drupal/layout/LayoutBundle.php b/core/modules/layout/lib/Drupal/layout/LayoutBundle.php
index 1591b6e..92b4796 100644
--- a/core/modules/layout/lib/Drupal/layout/LayoutBundle.php
+++ b/core/modules/layout/lib/Drupal/layout/LayoutBundle.php
@@ -18,7 +18,7 @@ class LayoutBundle extends Bundle {
    * Overrides Symfony\Component\HttpKernel\Bundle\Bundle.
    */
   public function build(ContainerBuilder $container) {
-    // register the LayoutManager class with the dependency injection container.
+    // Register the LayoutManager class with the dependency injection container.
     $container->register('plugin.manager.layout', 'Drupal\layout\Plugin\Type\LayoutManager');
   }
-}
\ No newline at end of file
+}
diff --git a/core/modules/layout/lib/Drupal/layout/Plugin/Derivative/Layout.php b/core/modules/layout/lib/Drupal/layout/Plugin/Derivative/Layout.php
index a598242..f7a9146 100644
--- a/core/modules/layout/lib/Drupal/layout/Plugin/Derivative/Layout.php
+++ b/core/modules/layout/lib/Drupal/layout/Plugin/Derivative/Layout.php
@@ -1,5 +1,10 @@
 <?php
 
+/**
+ * @file
+ * Definition of Drupal\layout\Plugin\Derivative\Layout.
+ */
+
 namespace Drupal\layout\Plugin\Derivative;
 
 use DirectoryIterator;
@@ -49,6 +54,9 @@ class Layout implements DerivativeInterface {
     return $this->derivatives;
   }
 
+  /**
+   * Finds layout definitions by looking for layout metadata.
+   */
   protected function iterateDirectories($dir, $provider) {
     $directories = new DirectoryIterator($dir);
     foreach ($directories as $fileinfo) {
diff --git a/core/modules/layout/lib/Drupal/layout/Plugin/LayoutInterface.php b/core/modules/layout/lib/Drupal/layout/Plugin/LayoutInterface.php
index 43410f8..0863a67 100644
--- a/core/modules/layout/lib/Drupal/layout/Plugin/LayoutInterface.php
+++ b/core/modules/layout/lib/Drupal/layout/Plugin/LayoutInterface.php
@@ -1,9 +1,27 @@
 <?php
 
+/**
+ * @file
+ * Definition of Drupal\layout\Plugin\LayoutInterface.
+ */
+
 namespace Drupal\layout\Plugin;
 
 interface LayoutInterface {
+
+  /**
+   * Returns a list of regions.
+   *
+   * @return array
+   *   An array of region machine names.
+   */
   public function getRegions();
 
+  /**
+   * Renders layout and returns the rendered markup.
+   *
+   * @return string
+   *   Rendered HTML output from the layout.
+   */
   public function renderLayout();
 }
diff --git a/core/modules/layout/lib/Drupal/layout/Plugin/Type/LayoutManager.php b/core/modules/layout/lib/Drupal/layout/Plugin/Type/LayoutManager.php
index 386b661..c03baa8 100644
--- a/core/modules/layout/lib/Drupal/layout/Plugin/Type/LayoutManager.php
+++ b/core/modules/layout/lib/Drupal/layout/Plugin/Type/LayoutManager.php
@@ -1,5 +1,10 @@
 <?php
 
+/**
+ * @file
+ * Definition of Drupal\layout\Plugin\Type\LayoutManager.
+ */
+
 namespace Drupal\layout\Plugin\Type;
 
 use Drupal\Component\Plugin\PluginManagerBase;
@@ -16,4 +21,4 @@ class LayoutManager extends PluginManagerBase {
     $this->discovery = new DerivativeDiscoveryDecorator(new AnnotatedClassDiscovery('layout', 'layout'));
     $this->factory = new ReflectionFactory($this);
   }
-}
\ No newline at end of file
+}
diff --git a/core/modules/layout/lib/Drupal/layout/Plugin/layout/layout/DefaultLayout.php b/core/modules/layout/lib/Drupal/layout/Plugin/layout/layout/DefaultLayout.php
index def7fdc..f9937ca 100644
--- a/core/modules/layout/lib/Drupal/layout/Plugin/layout/layout/DefaultLayout.php
+++ b/core/modules/layout/lib/Drupal/layout/Plugin/layout/layout/DefaultLayout.php
@@ -1,5 +1,10 @@
 <?php
 
+/**
+ * @file
+ * Definition of Drupal\layout\Plugin\layout\layout\DefaultLayout.
+ */
+
 namespace Drupal\layout\Plugin\layout\layout;
 
 use Drupal\layout\Plugin\LayoutInterface;
@@ -13,32 +18,50 @@ use Drupal\Core\Annotation\Plugin;
  * )
  */
 class DefaultLayout extends PluginBase implements LayoutInterface {
+
+  /**
+   * Overrides Drupal\layout\Plugin\LayoutInterface::getRegions().
+   */
   public function getRegions() {
     $definition = $this->getDefinition();
     return $definition['regions'];
   }
 
-  public function getCss() {
+  /**
+   * Add the CSS files associated with this layout to the page.
+   */
+  public function addCss() {
     $definition = $this->getDefinition();
     drupal_add_css($definition['path'] . '/' . $definition['css']);
   }
 
-  public function getAdminCss() {
+  /**
+   * Add the administrative CSS files associated with this layout to the page.
+   */
+  public function addAdminCss() {
     $definition = $this->getDefinition();
     $css = isset($definition['admin css']) ? $definition['admin css'] : $definition['css'];
     drupal_add_css($definition['path'] . '/' . $css);
   }
 
-  public function getJs() {
+  /**
+   * Add the JS files associated with this layout to the page.
+   */
+  public function addJs() {
     $definition = $this->getDefinition();
     if (isset($definition['js']))  {
       drupal_add_js($definition['path'] . '/' . $definition['js']);
     }
   }
 
-  // @todo The $regions parameter is here only temporarily. It allows the caller
-  //   to pass already rendered regions, while layout/block configuration code
-  //   is still in progress.
+  /**
+   * Overrides Drupal\layout\Plugin\LayoutInterface::renderLayout().
+   *
+   * @todo
+   *   The $regions parameter is here only temporarily. It allows the caller
+   *   to pass already rendered regions, while layout/block configuration code
+   *   is still in progress.
+   */
   public function renderLayout($admin = FALSE, $regions = array()) {
     $definition = $this->getDefinition();
 
@@ -63,11 +86,11 @@ class DefaultLayout extends PluginBase implements LayoutInterface {
     }
 
     if (!$admin) {
-      $this->getCss();
-      $this->getJs();
+      $this->addCss();
+      $this->addJs();
     }
     else {
-      $this->getAdminCss();
+      $this->addAdminCss();
     }
 
     $template = $definition['path'] . '/' . $definition['template'] . '.tpl.php';
diff --git a/core/themes/bartik/layout/page/page.yml b/core/themes/bartik/layout/page/page.yml
index 618eb73..7ed50bb 100644
--- a/core/themes/bartik/layout/page/page.yml
+++ b/core/themes/bartik/layout/page/page.yml
@@ -1,7 +1,7 @@
-title: Bartik
+title: Bartik page
 category: Other
-icon: bartik.png
-css: bartik.css
+icon: page.png
+css: page.css
 regions:
   header: 'Header'
   help: 'Help'