diff --git a/administrator/components/com_categories/forms/category.xml b/administrator/components/com_categories/forms/category.xml
index 61a5053e5c3b6..1f1dc926ec352 100644
--- a/administrator/components/com_categories/forms/category.xml
+++ b/administrator/components/com_categories/forms/category.xml
@@ -204,7 +204,6 @@
 		name="tags"
 		type="tag"
 		label="JTAG"
-		class="col-sm-12"
 		multiple="true"
 	/>
 
diff --git a/administrator/components/com_fields/forms/field.xml b/administrator/components/com_fields/forms/field.xml
index 17906b556b1d9..571bd83d59b83 100644
--- a/administrator/components/com_fields/forms/field.xml
+++ b/administrator/components/com_fields/forms/field.xml
@@ -266,10 +266,9 @@
 
 			<field
 				name="display_readonly"
-				type="radio"
+				type="list"
 				label="JFIELD_DISPLAY_READONLY_LABEL"
 				description="JFIELD_DISPLAY_READONLY_DESC"
-				class="btn-group btn-group-yesno"
 				default="2"
 				>
 				<option value="2">JGLOBAL_INHERIT</option>
diff --git a/administrator/components/com_menus/Controller/MenuController.php b/administrator/components/com_menus/Controller/MenuController.php
index 2c45deaba555f..017d690adfed5 100644
--- a/administrator/components/com_menus/Controller/MenuController.php
+++ b/administrator/components/com_menus/Controller/MenuController.php
@@ -76,7 +76,7 @@ public function save($key = null, $urlVar = null)
 
 		// Get the model and attempt to validate the posted data.
 		/* @var \Joomla\Component\Menus\Administrator\Model\MenuModel $model */
-		$model = $this->getModel('Menu');
+		$model = $this->getModel('Menu', '', ['ignore_request' => false]);
 		$form  = $model->getForm();
 
 		if (!$form)
diff --git a/administrator/components/com_menus/Field/MenuPresetField.php b/administrator/components/com_menus/Field/MenuPresetField.php
index 22310a786d6a0..66eeaa548589d 100644
--- a/administrator/components/com_menus/Field/MenuPresetField.php
+++ b/administrator/components/com_menus/Field/MenuPresetField.php
@@ -14,7 +14,7 @@
 use Joomla\CMS\Form\Field\ListField;
 use Joomla\CMS\HTML\HTMLHelper;
 use Joomla\CMS\Language\Text;
-use Joomla\CMS\Menu\MenuHelper;
+use Joomla\Component\Menus\Administrator\Helper\MenusHelper;
 
 /**
  * Administrator Menu Presets list field.
@@ -42,7 +42,7 @@ class MenuPresetField extends ListField
 	protected function getOptions()
 	{
 		$options = array();
-		$presets = MenuHelper::getPresets();
+		$presets = MenusHelper::getPresets();
 
 		foreach ($presets as $preset)
 		{
diff --git a/administrator/components/com_menus/Helper/MenusHelper.php b/administrator/components/com_menus/Helper/MenusHelper.php
index 07427b3b8bd5b..daf3457ca0c22 100644
--- a/administrator/components/com_menus/Helper/MenusHelper.php
+++ b/administrator/components/com_menus/Helper/MenusHelper.php
@@ -12,11 +12,12 @@
 defined('_JEXEC') or die;
 
 use Joomla\CMS\Factory;
+use Joomla\CMS\Filesystem\Folder;
 use Joomla\CMS\Helper\ContentHelper;
 use Joomla\CMS\Language\Associations;
 use Joomla\CMS\Language\Multilanguage;
 use Joomla\CMS\Language\Text;
-use Joomla\CMS\Menu\MenuHelper;
+use Joomla\CMS\Menu\MenuItem;
 use Joomla\CMS\Table\Table;
 use Joomla\Database\DatabaseInterface;
 use Joomla\Registry\Registry;
@@ -34,6 +35,15 @@ class MenusHelper extends ContentHelper
 	 */
 	protected static $_filter = array('option', 'view', 'layout');
 
+	/**
+	 * List of preset include paths
+	 *
+	 * @var  array
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	protected static $presets = null;
+
 	/**
 	 * Gets a standard form of a link for lookups.
 	 *
@@ -290,12 +300,13 @@ public static function getAssociations($pk)
 	 * @param   boolean  $enabledOnly  Whether to load only enabled/published menu items.
 	 * @param   int[]    $exclude      The menu items to exclude from the list
 	 *
-	 * @return  array
+	 * @return  MenuItem  A root node with the menu items as children
 	 *
-	 * @since   3.8.0
+	 * @since   __DEPLOY_VERSION__
 	 */
 	public static function getMenuItems($menutype, $enabledOnly = false, $exclude = array())
 	{
+		$root = new MenuItem;
 		$db    = Factory::getContainer()->get(DatabaseInterface::class);
 		$query = $db->getQuery(true);
 
@@ -340,21 +351,45 @@ public static function getMenuItems($menutype, $enabledOnly = false, $exclude =
 
 		try
 		{
-			$menuItems = $db->loadObjectList();
+			$menuItems = $db->loadObjectList('id', '\Joomla\CMS\Menu\MenuItem');
 
-			foreach ($menuItems as &$menuitem)
+			foreach ($menuItems as $menuitem)
 			{
 				$menuitem->params = new Registry($menuitem->params);
+
+				// Resolve the alias item to get the original item
+				if ($menuitem->type == 'alias')
+				{
+					static::resolveAlias($menuitem);
+				}
+
+				if ($menuitem->link = in_array($menuitem->type, array('separator', 'heading', 'container')) ? '#' : trim($menuitem->link))
+				{
+					$menuitem->submenu    = array();
+					$menuitem->class      = $menuitem->img ?? '';
+					$menuitem->scope      = $menuitem->scope ?? null;
+					$menuitem->browserNav = $menuitem->browserNav ? '_blank' : '';
+				}
+
+				if ($menuitem->parent_id > 1)
+				{
+					if (isset($menuItems[$menuitem->parent_id]))
+					{
+						$menuItems[$menuitem->parent_id]->addChild($menuitem);
+					}
+				}
+				else
+				{
+					$root->addChild($menuitem);
+				}
 			}
 		}
 		catch (\RuntimeException $e)
 		{
-			$menuItems = array();
-
 			Factory::getApplication()->enqueueMessage(Text::_('JERROR_AN_ERROR_HAS_OCCURRED'), 'error');
 		}
 
-		return $menuItems;
+		return $root;
 	}
 
 	/**
@@ -367,37 +402,37 @@ public static function getMenuItems($menutype, $enabledOnly = false, $exclude =
 	 *
 	 * @throws  \Exception
 	 *
-	 * @since   3.8.0
+	 * @since   __DEPLOY_VERSION__
 	 */
 	public static function installPreset($preset, $menutype)
 	{
-		$items = MenuHelper::loadPreset($preset, false);
+		$root = static::loadPreset($preset, false);
 
-		if (count($items) == 0)
+		if (count($root->getChildren()) == 0)
 		{
 			throw new \Exception(Text::_('COM_MENUS_PRESET_LOAD_FAILED'));
 		}
 
-		static::installPresetItems($items, $menutype, 1);
+		static::installPresetItems($root, $menutype, 1);
 	}
 
 	/**
 	 * Method to install a preset menu item into database and link it to the given menutype
 	 *
-	 * @param   \stdClass[]  $items     The single menuitem instance with a list of its descendants
-	 * @param   string       $menutype  The target menutype
-	 * @param   int          $parent    The parent id or object
+	 * @param   MenuItem  $node      The parent node of the items to process
+	 * @param   string    $menutype  The target menutype
 	 *
 	 * @return  void
 	 *
 	 * @throws  \Exception
 	 *
-	 * @since   3.8.0
+	 * @since   __DEPLOY_VERSION__
 	 */
-	protected static function installPresetItems(&$items, $menutype, $parent = 1)
+	protected static function installPresetItems($node, $menutype)
 	{
 		$db    = Factory::getDbo();
 		$query = $db->getQuery(true);
+		$items = $node->getChildren();
 
 		static $components = array();
 
@@ -410,7 +445,7 @@ protected static function installPresetItems(&$items, $menutype, $parent = 1)
 
 		Factory::getApplication()->triggerEvent('onPreprocessMenuItems', array('com_menus.administrator.import', &$items, null, true));
 
-		foreach ($items as &$item)
+		foreach ($items as $item)
 		{
 			/** @var  \JTableMenu  $table */
 			$table = Table::getInstance('Menu');
@@ -430,7 +465,7 @@ protected static function installPresetItems(&$items, $menutype, $parent = 1)
 					'menutype'  => $menutype,
 					'type'      => $item->type,
 					'title'     => $item->title,
-					'parent_id' => $parent,
+					'parent_id' => $item->getParent()->id,
 					'client_id' => 1,
 				);
 				$table->load($keys);
@@ -456,7 +491,7 @@ protected static function installPresetItems(&$items, $menutype, $parent = 1)
 					'menutype'  => $menutype,
 					'type'      => $item->type,
 					'link'      => $item->link,
-					'parent_id' => $parent,
+					'parent_id' => $item->getParent()->id,
 					'client_id' => 1,
 				);
 				$table->load($keys);
@@ -489,7 +524,7 @@ protected static function installPresetItems(&$items, $menutype, $parent = 1)
 				'img'          => $item->class,
 				'access'       => $item->access,
 				'component_id' => array_search($item->element, $components) ?: 0,
-				'parent_id'    => $parent,
+				'parent_id'    => $item->getParent()->id,
 				'client_id'    => 1,
 				'published'    => 1,
 				'language'     => '*',
@@ -502,7 +537,7 @@ protected static function installPresetItems(&$items, $menutype, $parent = 1)
 				throw new \Exception('Bind failed: ' . $table->getError());
 			}
 
-			$table->setLocation($parent, 'last-child');
+			$table->setLocation($item->getParent()->id, 'last-child');
 
 			if (!$table->check())
 			{
@@ -516,10 +551,351 @@ protected static function installPresetItems(&$items, $menutype, $parent = 1)
 
 			$item->id = $table->get('id');
 
-			if (!empty($item->submenu))
+			if ($item->hasChildren())
 			{
-				static::installPresetItems($item->submenu, $menutype, $item->id);
+				static::installPresetItems($item, $menutype);
 			}
 		}
 	}
+
+	/**
+	 * Add a custom preset externally via plugin or any other means.
+	 * WARNING: Presets with same name will replace previously added preset *except* Joomla's default preset (joomla)
+	 *
+	 * @param   string  $name     The unique identifier for the preset.
+	 * @param   string  $title    The display label for the preset.
+	 * @param   string  $path     The path to the preset file.
+	 * @param   bool    $replace  Whether to replace the preset with the same name if any (except 'joomla').
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public static function addPreset($name, $title, $path, $replace = true)
+	{
+		if (static::$presets === null)
+		{
+			static::getPresets();
+		}
+
+		if ($name == 'joomla')
+		{
+			$replace = false;
+		}
+
+		if (($replace || !array_key_exists($name, static::$presets)) && is_file($path))
+		{
+			$preset = new \stdClass;
+
+			$preset->name  = $name;
+			$preset->title = $title;
+			$preset->path  = $path;
+
+			static::$presets[$name] = $preset;
+		}
+	}
+
+	/**
+	 * Get a list of available presets.
+	 *
+	 * @return  \stdClass[]
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public static function getPresets()
+	{
+		if (static::$presets === null)
+		{
+			// Important: 'null' will cause infinite recursion.
+			static::$presets = array();
+
+			static::addPreset('joomla', 'JLIB_MENUS_PRESET_JOOMLA', JPATH_ADMINISTRATOR . '/components/com_menus/presets/joomla.xml');
+			static::addPreset('modern', 'JLIB_MENUS_PRESET_MODERN', JPATH_ADMINISTRATOR . '/components/com_menus/presets/modern.xml');
+
+			// Load from template folder automatically
+			$app = Factory::getApplication();
+			$tpl = JPATH_THEMES . '/' . $app->getTemplate() . '/html/com_menus/presets';
+
+			if (is_dir($tpl))
+			{
+				$files = Folder::files($tpl, '\.xml$');
+
+				foreach ($files as $file)
+				{
+					$name  = substr($file, 0, -4);
+					$title = str_replace('-', ' ', $name);
+
+					static::addPreset(strtolower($name), ucwords($title), $tpl . '/' . $file);
+				}
+			}
+		}
+
+		return static::$presets;
+	}
+
+	/**
+	 * Load the menu items from a preset file into a hierarchical list of objects
+	 *
+	 * @param   string    $name      The preset name
+	 * @param   bool      $fallback  Fallback to default (joomla) preset if the specified one could not be loaded?
+	 * @param   MenuItem  $parent    Root node of the menu
+	 *
+	 * @return  MenuItem
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public static function loadPreset($name, $fallback = true, $parent = null)
+	{
+		$presets = static::getPresets();
+
+		if (!$parent)
+		{
+			$parent = new MenuItem;
+		}
+
+		if (isset($presets[$name]) && ($xml = simplexml_load_file($presets[$name]->path, null, LIBXML_NOCDATA)) && $xml instanceof \SimpleXMLElement)
+		{
+			static::loadXml($xml, $parent);
+		}
+		elseif ($fallback && isset($presets['joomla']))
+		{
+			if (($xml = simplexml_load_file($presets['joomla']->path, null, LIBXML_NOCDATA)) && $xml instanceof \SimpleXMLElement)
+			{
+				static::loadXml($xml, $parent);
+			}
+		}
+
+		return $parent;
+	}
+
+	/**
+	 * Method to resolve the menu item alias type menu item
+	 *
+	 * @param   \stdClass  &$item  The alias object
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public static function resolveAlias(&$item)
+	{
+		$obj = $item;
+
+		while ($obj->type == 'alias')
+		{
+			$params  = new Registry($obj->params);
+			$aliasTo = $params->get('aliasoptions');
+
+			$db = Factory::getDbo();
+			$query = $db->getQuery(true);
+			$query->select('a.id, a.link, a.type, e.element')
+				->from('#__menu a')
+				->where('a.id = ' . (int) $aliasTo)
+				->join('left', '#__extensions e ON e.id = a.component_id = e.id');
+
+			try
+			{
+				$obj = $db->setQuery($query)->loadObject();
+
+				if (!$obj)
+				{
+					$item->link = '';
+
+					return;
+				}
+			}
+			catch (\Exception $e)
+			{
+				$item->link = '';
+
+				return;
+			}
+		}
+
+		$item->id      = $obj->id;
+		$item->link    = $obj->link;
+		$item->type    = $obj->type;
+		$item->element = $obj->element;
+	}
+
+	/**
+	 * Parse the flat list of menu items and prepare the hierarchy of them using parent-child relationship.
+	 *
+	 * @param   MenuItem  $item  Menu item to preprocess
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public static function preprocess($item)
+	{
+		// Resolve the alias item to get the original item
+		if ($item->type == 'alias')
+		{
+			static::resolveAlias($item);
+		}
+
+		if ($item->link = in_array($item->type, array('separator', 'heading', 'container')) ? '#' : trim($item->link))
+		{
+			$item->submenu    = array();
+			$item->class      = $item->img ?? '';
+			$item->scope      = $item->scope ?? null;
+			$item->browserNav = $item->browserNav ? '_blank' : '';
+		}
+	}
+
+	/**
+	 * Load a menu tree from an XML file
+	 *
+	 * @param   \SimpleXMLElement[]  $elements  The xml menuitem nodes
+	 * @param   MenuItem             $parent    The menu hierarchy list to be populated
+	 * @param   string[]             $replace   The substring replacements for iterator type items
+	 *
+	 * @return  void
+	 *
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected static function loadXml($elements, $parent, $replace = array())
+	{
+		foreach ($elements as $element)
+		{
+			if ($element->getName() != 'menuitem')
+			{
+				continue;
+			}
+
+			$select = (string) $element['sql_select'];
+			$from   = (string) $element['sql_from'];
+
+			/**
+			 * Following is a repeatable group based on simple database query. This requires sql_* attributes (sql_select and sql_from are required)
+			 * The values can be used like - "{sql:columnName}" in any attribute of repeated elements.
+			 * The repeated elements are place inside this xml node but they will be populated in the same level in the rendered menu
+			 */
+			if ($select && $from)
+			{
+				$hidden = $element['hidden'] == 'true';
+				$where  = (string) $element['sql_where'];
+				$order  = (string) $element['sql_order'];
+				$group  = (string) $element['sql_group'];
+				$lJoin  = (string) $element['sql_leftjoin'];
+				$iJoin  = (string) $element['sql_innerjoin'];
+
+				$db    = Factory::getDbo();
+				$query = $db->getQuery(true);
+				$query->select($select)->from($from);
+
+				if ($where)
+				{
+					$query->where($where);
+				}
+
+				if ($order)
+				{
+					$query->order($order);
+				}
+
+				if ($group)
+				{
+					$query->group($group);
+				}
+
+				if ($lJoin)
+				{
+					$query->leftJoin($lJoin);
+				}
+
+				if ($iJoin)
+				{
+					$query->innerJoin($iJoin);
+				}
+
+				$results = $db->setQuery($query)->loadObjectList();
+
+				// Skip the entire group if no items to iterate over.
+				if ($results)
+				{
+					// Show the repeatable group heading node only if not set as hidden.
+					if (!$hidden)
+					{
+						$child = static::parseXmlNode($element, $replace);
+						$parent->addChild($child);
+					}
+
+					// Iterate over the matching records, items goes in the same level (not $item->submenu) as this node.
+					foreach ($results as $result)
+					{
+						static::loadXml($element->menuitem, $parent, $result);
+					}
+				}
+			}
+			else
+			{
+				$item = static::parseXmlNode($element, $replace);
+
+				// Process the child nodes
+				static::loadXml($element->menuitem, $item, $replace);
+
+				$parent->addChild($item);
+			}
+		}
+	}
+
+	/**
+	 * Create a menu item node from an xml element
+	 *
+	 * @param   \SimpleXMLElement  $node     A menuitem element from preset xml
+	 * @param   string[]           $replace  The values to substitute in the title, link and element texts
+	 *
+	 * @return  \stdClass
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	protected static function parseXmlNode($node, $replace = array())
+	{
+		$item = new MenuItem;
+
+		$item->id         = null;
+		$item->type       = (string) $node['type'];
+		$item->title      = (string) $node['title'];
+		$item->link       = (string) $node['link'];
+		$item->element    = (string) $node['element'];
+		$item->class      = (string) $node['class'];
+		$item->icon       = (string) $node['icon'];
+		$item->browserNav = (string) $node['target'];
+		$item->access     = (int) $node['access'];
+		$item->scope      = (string) $node['scope'] ?: 'default';
+		$item->setParams(new Registry(trim($node->params)));
+		$item->getParams()->set('menu-permission', (string) $node['permission']);
+
+		if ($item->type == 'separator' && trim($item->title, '- '))
+		{
+			$item->getParams()->set('text_separator', 1);
+		}
+
+		if ($item->type == 'heading' || $item->type == 'container')
+		{
+			$item->link = '#';
+		}
+
+		if ((string) $node['quicktask'])
+		{
+			$item->getParams()->set('menu-quicktask', (string) $node['quicktask']);
+			$item->getParams()->set('menu-quicktask-title', (string) $node['quicktask-title']);
+			$item->getParams()->set('menu-quicktask-icon', (string) $node['quicktask-icon']);
+			$item->getParams()->set('menu-quicktask-permission', (string) $node['quicktask-permission']);
+		}
+
+		// Translate attributes for iterator values
+		foreach ($replace as $var => $val)
+		{
+			$item->title   = str_replace("{sql:$var}", $val, $item->title);
+			$item->element = str_replace("{sql:$var}", $val, $item->element);
+			$item->link    = str_replace("{sql:$var}", $val, $item->link);
+			$item->class   = str_replace("{sql:$var}", $val, $item->class);
+			$item->icon    = str_replace("{sql:$var}", $val, $item->icon);
+		}
+
+		return $item;
+	}
 }
diff --git a/administrator/components/com_menus/View/Menu/XmlView.php b/administrator/components/com_menus/View/Menu/XmlView.php
index 71bb461b2010d..497449e246367 100644
--- a/administrator/components/com_menus/View/Menu/XmlView.php
+++ b/administrator/components/com_menus/View/Menu/XmlView.php
@@ -56,10 +56,10 @@ public function display($tpl = null)
 
 		if ($menutype)
 		{
-			$items = MenusHelper::getMenuItems($menutype, true);
+			$root = MenusHelper::getMenuItems($menutype, true);
 		}
 
-		if (empty($items))
+		if ($root->hasChildren())
 		{
 			Log::add(Text::_('COM_MENUS_SELECT_MENU_FIRST_EXPORT'), Log::WARNING, 'jerror');
 
@@ -68,7 +68,7 @@ public function display($tpl = null)
 			return;
 		}
 
-		$this->items = MenuHelper::createLevels($items);
+		$this->items = $root->getChildren();
 
 		$xml = new \SimpleXMLElement('<menu ' .
 			'xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ' .
diff --git a/administrator/components/com_menus/presets/joomla.xml b/administrator/components/com_menus/presets/joomla.xml
index f261a5915f29a..d866d767c5d44 100644
--- a/administrator/components/com_menus/presets/joomla.xml
+++ b/administrator/components/com_menus/presets/joomla.xml
@@ -20,13 +20,18 @@
 				title="MOD_MENU_COM_CONTENT_ARTICLE_MANAGER"
 				type="component"
 				element="com_content"
-				link="index.php?option=com_content">
+				link="index.php?option=com_content"
+				quicktask="index.php?option=com_content&amp;task=article.add"
+				quicktask-title="MOD_MENU_COM_CONTENT_ARTICLE_ADD"
+				>
 		</menuitem>
 		<menuitem
 				title="MOD_MENU_COM_CONTENT_CATEGORY_MANAGER"
 				type="component"
 				element="com_categories"
-				link="index.php?option=com_categories&amp;extension=com_content">
+				link="index.php?option=com_categories&amp;extension=com_content"
+				quicktask="index.php?option=com_categories&amp;extension=com_content&amp;task=category.add"
+				>
 		</menuitem>
 		<menuitem
 				title="MOD_MENU_COM_CONTENT_FEATURED"
@@ -138,14 +143,9 @@
 					title="{sql:title}"
 					type="component"
 					element="com_menus"
-					link="index.php?option=com_menus&amp;view=items&amp;menutype={sql:menutype}">
-				<menuitem
-						title="MOD_MENU_MENU_MANAGER_NEW_MENU_ITEM"
-						type="component"
-						element="com_menus"
-						link="index.php?option=com_menus&amp;view=item&amp;layout=edit&amp;menutype={sql:menutype}"
-						scope="edit"
-				/>
+					link="index.php?option=com_menus&amp;view=items&amp;menutype={sql:menutype}"
+					icon="{sql:icon}"
+					class="class:menu">
 			</menuitem>
 		</menuitem>
 	</menuitem>
diff --git a/administrator/components/com_modules/tmpl/module/edit_assignment.php b/administrator/components/com_modules/tmpl/module/edit_assignment.php
index bf9c2470c298e..9ddd1fdf68109 100644
--- a/administrator/components/com_modules/tmpl/module/edit_assignment.php
+++ b/administrator/components/com_modules/tmpl/module/edit_assignment.php
@@ -22,7 +22,7 @@
 HTMLHelper::_('script', 'com_modules/admin-module-edit_assignment.min.js', array('version' => 'auto', 'relative' => true));
 ?>
 <div class="control-group">
-	<label id="jform_menus-lbl" class="control-label" for="jform_menus"><?php echo Text::_('COM_MODULES_MODULE_ASSIGN'); ?></label>
+	<label id="jform_menus-lbl" class="control-label" for="jform_assignment"><?php echo Text::_('COM_MODULES_MODULE_ASSIGN'); ?></label>
 	<div id="jform_menus" class="controls">
 		<select class="custom-select" name="jform[assignment]" id="jform_assignment">
 			<?php echo HTMLHelper::_('select.options', ModulesHelper::getAssignmentOptions($this->item->client_id), 'value', 'text', $this->item->assignment, true); ?>
diff --git a/administrator/components/com_templates/tmpl/template/default_updated_files.php b/administrator/components/com_templates/tmpl/template/default_updated_files.php
index 4d41c3615ef37..a7f38bb5fe319 100644
--- a/administrator/components/com_templates/tmpl/template/default_updated_files.php
+++ b/administrator/components/com_templates/tmpl/template/default_updated_files.php
@@ -40,7 +40,7 @@
 								<?php echo Text::_('COM_TEMPLATES_OVERRIDE_MODIFIED_DATE'); ?>
 							</th>
 							<th scope="col">
-								<?php echo Text::_('COM_TEMPLATES_OVERRIDE_ACTION'); ?>
+								<?php echo Text::_('COM_TEMPLATES_OVERRIDE_SOURCE'); ?>
 							</th>
 						</tr>
 					</thead>
diff --git a/administrator/language/en-GB/en-GB.com_templates.ini b/administrator/language/en-GB/en-GB.com_templates.ini
index 2397b13aa79fd..3617520518596 100644
--- a/administrator/language/en-GB/en-GB.com_templates.ini
+++ b/administrator/language/en-GB/en-GB.com_templates.ini
@@ -179,13 +179,13 @@ COM_TEMPLATES_NEW_FILE_TYPE="File Type"
 COM_TEMPLATES_NO_TEMPLATE_SELECTED="No template selected."
 COM_TEMPLATES_OPTION_NONE=":: None ::"
 COM_TEMPLATES_OPTION_SELECT_MENU_ITEM="- Select Menu Item -"
-COM_TEMPLATES_OVERRIDE_ACTION="Update Action"
 COM_TEMPLATES_OVERRIDE_CHECKED="Checked"
 COM_TEMPLATES_OVERRIDE_CREATED="Override created in "
 COM_TEMPLATES_OVERRIDE_CREATED_DATE="Added to the list"
 COM_TEMPLATES_OVERRIDE_CORE_REMOVED="Original file removed"
 COM_TEMPLATES_OVERRIDE_FAILED="Failed to create override."
 COM_TEMPLATES_OVERRIDE_MODIFIED_DATE="Last change via Update"
+COM_TEMPLATES_OVERRIDE_SOURCE="Update Source"
 COM_TEMPLATES_OVERRIDE_SUCCESS="Successfully created the override."
 COM_TEMPLATES_OVERRIDE_TEMPLATE_FILE="Template File"
 COM_TEMPLATES_OVERRIDE_UPTODATE="Overridden files are up to date. Nothing has been changed in the last extension or Joomla update."
diff --git a/administrator/modules/mod_menu/Helper/MenuHelper.php b/administrator/modules/mod_menu/Helper/MenuHelper.php
deleted file mode 100644
index 16632e2b9ad2a..0000000000000
--- a/administrator/modules/mod_menu/Helper/MenuHelper.php
+++ /dev/null
@@ -1,65 +0,0 @@
-<?php
-/**
- * @package     Joomla.Administrator
- * @subpackage  mod_menu
- *
- * @copyright   Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license     GNU General Public License version 2 or later; see LICENSE.txt
- */
-
-namespace Joomla\Module\Menu\Administrator\Menu;
-
-defined('_JEXEC') or die;
-
-use Joomla\CMS\Factory;
-use Joomla\CMS\Language\Text;
-
-/**
- * Helper for mod_menu
- *
- * @since  1.5
- */
-abstract class MenuHelper
-{
-	/**
-	 * Get a list of the available menus.
-	 *
-	 * @return  array  An array of the available menus (from the menu types table).
-	 *
-	 * @since   1.6
-	 */
-	public static function getItems()
-	{
-		$db = Factory::getDbo();
-
-		// Search for home menu and language if exists
-		$subQuery = $db->getQuery(true)
-			->select('b.menutype, b.home, b.language, l.image, l.sef, l.title_native')
-			->from('#__menu AS b')
-			->leftJoin('#__languages AS l ON l.lang_code = b.language')
-			->where('b.home != 0')
-			->where('(b.client_id = 0 OR b.client_id IS NULL)');
-
-		// Get all menu types with optional home menu and language
-		$query = $db->getQuery(true)
-			->select('a.id, a.asset_id, a.menutype, a.title, a.description, a.client_id')
-			->select('c.home, c.language, c.image, c.sef, c.title_native')
-			->from('#__menu_types AS a')
-			->leftJoin('(' . (string) $subQuery . ') c ON c.menutype = a.menutype')
-			->order('a.id');
-
-		$db->setQuery($query);
-
-		try
-		{
-			$result = $db->loadObjectList();
-		}
-		catch (\RuntimeException $e)
-		{
-			$result = array();
-			Factory::getApplication()->enqueueMessage(Text::sprintf('JERROR_LOADING_MENUS', $e->getMessage()), 'error');
-		}
-
-		return $result;
-	}
-}
diff --git a/administrator/modules/mod_menu/Menu/CssMenu.php b/administrator/modules/mod_menu/Menu/CssMenu.php
index 9054026f1c5fa..327504dfb0244 100644
--- a/administrator/modules/mod_menu/Menu/CssMenu.php
+++ b/administrator/modules/mod_menu/Menu/CssMenu.php
@@ -14,9 +14,7 @@
 use Joomla\CMS\Application\CMSApplication;
 use Joomla\CMS\Component\ComponentHelper;
 use Joomla\CMS\Language\Text;
-use Joomla\CMS\Menu\MenuHelper;
-use Joomla\CMS\Menu\Node;
-use Joomla\CMS\Menu\Tree;
+use Joomla\CMS\Menu\MenuItem;
 use Joomla\CMS\Table\Table;
 use Joomla\CMS\Uri\Uri;
 use Joomla\Component\Menus\Administrator\Helper\MenusHelper;
@@ -31,13 +29,22 @@
 class CssMenu
 {
 	/**
-	 * The Menu tree object
+	 * The root of the menu
 	 *
-	 * @var    Tree
+	 * @var    MenuItem
 	 *
-	 * @since  3.8.0
+	 * @since  __DEPLOY_VERSION__
 	 */
-	protected $tree;
+	protected $root;
+
+	/**
+	 * An array of MenuItem nodes
+	 *
+	 * @var    MenuItem[]
+	 *
+	 * @since  __DEPLOY_VERSION__
+	 */
+	protected $nodes = [];
 
 	/**
 	 * The module options
@@ -67,32 +74,25 @@ class CssMenu
 	protected $application;
 
 	/**
-	 * CssMenu constructor.
+	 * A counter for unique IDs
 	 *
-	 * @param   CMSApplication  $application  The application
+	 * @var   int
 	 *
-	 * @since 4.0.0
+	 * @since  __DEPLOY_VERSION__
 	 */
-	public function __construct(CMSApplication $application)
-	{
-		$this->application = $application;
-	}
+	protected $counter = 0;
 
 	/**
-	 * Get the current menu tree
+	 * CssMenu constructor.
 	 *
-	 * @return  Tree
+	 * @param   CMSApplication  $application  The application
 	 *
-	 * @since   3.8.0
+	 * @since 4.0.0
 	 */
-	public function getTree()
+	public function __construct(CMSApplication $application)
 	{
-		if (!$this->tree)
-		{
-			$this->tree = new Tree;
-		}
-
-		return $this->tree;
+		$this->application = $application;
+		$this->root = new MenuItem;
 	}
 
 	/**
@@ -101,13 +101,12 @@ public function getTree()
 	 * @param   Registry  $params   Menu configuration parameters
 	 * @param   bool      $enabled  Whether the menu should be enabled or disabled
 	 *
-	 * @return  void
+	 * @return  MenuItem  Root node of the menu tree
 	 *
 	 * @since   3.7.0
 	 */
 	public function load($params, $enabled)
 	{
-		$this->tree    = $this->getTree();
 		$this->params  = $params;
 		$this->enabled = $enabled;
 		$menutype      = $this->params->get('menutype', '*');
@@ -115,64 +114,64 @@ public function load($params, $enabled)
 		if ($menutype === '*')
 		{
 			$name   = $this->params->get('preset', 'joomla');
-			$levels = MenuHelper::loadPreset($name);
+			$this->root = MenusHelper::loadPreset($name);
 		}
 		else
 		{
-			$items = MenusHelper::getMenuItems($menutype, true);
+			$this->root = MenusHelper::getMenuItems($menutype, true);
 
-			if ($this->enabled && $this->params->get('check', 1))
+			// Can we access everything important with this menu? Create a recovery menu!
+			if ($this->enabled
+				&& $this->params->get('check', 1)
+				&& $this->check($this->root, $this->params))
 			{
-				if ($this->check($items, $this->params))
-				{
-					$this->params->set('recovery', true);
+				$this->params->set('recovery', true);
 
-					// In recovery mode, load the preset inside a special root node.
-					$this->tree->addChild(new Node\Heading('MOD_MENU_RECOVERY_MENU_ROOT'), true);
+				// In recovery mode, load the preset inside a special root node.
+				$this->root = new MenuItem(['level' => 0]);
+				$heading = new MenuItem(['title' => 'MOD_MENU_RECOVERY_MENU_ROOT', 'type' => 'heading']);
+				$this->root->addChild($heading);
 
-					$levels = MenuHelper::loadPreset('joomla');
-					$levels = $this->preprocess($levels);
+				MenusHelper::loadPreset('joomla', true, $heading);
 
-					$this->populateTree($levels);
+				$this->preprocess($this->root);
 
-					$this->tree->addChild(new Node\Separator);
+				$this->root->addChild(new MenuItem(['type' => 'separator']));
 
-					// Add link to exit recovery mode
-					$uri = clone Uri::getInstance();
-					$uri->setVar('recover_menu', 0);
+				// Add link to exit recovery mode
+				$uri = clone Uri::getInstance();
+				$uri->setVar('recover_menu', 0);
 
-					$this->tree->addChild(new Node\Url('MOD_MENU_RECOVERY_EXIT', $uri->toString()));
+				$this->root->addChild(new MenuItem(['title' => 'MOD_MENU_RECOVERY_EXIT', 'type' => 'url', 'url' => $uri->toString()]));
 
-					$this->tree->getParent();
-				}
+				return $this->root;
 			}
-
-			$levels = MenuHelper::createLevels($items);
 		}
 
-		$levels = $this->preprocess($levels);
+		$this->preprocess($this->root);
 
-		$this->populateTree($levels);
+		return $this->root;
 	}
 
 	/**
 	 * Method to render a given level of a menu using provided layout file
 	 *
-	 * @param   string  $layoutFile  The layout file to be used to render
+	 * @param   string    $layoutFile  The layout file to be used to render
+	 * @param   MenuItem  $node        Node to render the children of
 	 *
 	 * @return  void
 	 *
 	 * @since   3.8.0
 	 */
-	public function renderSubmenu($layoutFile)
+	public function renderSubmenu($layoutFile, $node)
 	{
 		if (is_file($layoutFile))
 		{
-			$children = $this->tree->getCurrent()->getChildren();
+			$children = $node->getChildren();
 
-			foreach ($children as $child)
+			foreach ($children as $current)
 			{
-				$this->tree->setCurrent($child);
+				$current->level = $node->level + 1;
 
 				// This sets the scope to this object for the layout file and also isolates other `include`s
 				require $layoutFile;
@@ -183,14 +182,14 @@ public function renderSubmenu($layoutFile)
 	/**
 	 * Check the flat list of menu items for important links
 	 *
-	 * @param   array     $items   The menu items array
+	 * @param   MenuItem  $node    The menu items array
 	 * @param   Registry  $params  Module options
 	 *
 	 * @return  boolean  Whether to show recovery menu
 	 *
 	 * @since   3.8.0
 	 */
-	protected function check($items, Registry $params)
+	protected function check($node, Registry $params)
 	{
 		$me          = $this->application->getIdentity();
 		$authMenus   = $me->authorise('core.manage', 'com_menus');
@@ -201,6 +200,7 @@ protected function check($items, Registry $params)
 			return false;
 		}
 
+		$items      = $node->getChildren(true);
 		$types      = ArrayHelper::getColumn($items, 'type');
 		$elements   = ArrayHelper::getColumn($items, 'element');
 		$rMenu      = $authMenus && !in_array('com_menus', $elements);
@@ -253,29 +253,34 @@ protected function check($items, Registry $params)
 	/**
 	 * Filter and perform other preparatory tasks for loaded menu items based on access rights and module configurations for display
 	 *
-	 * @param   \stdClass[]  $items  The levelled array of menu item objects
+	 * @param   MenuItem  $parent  A menu item to process
 	 *
 	 * @return  array
 	 *
 	 * @since   3.8.0
 	 */
-	protected function preprocess($items)
+	protected function preprocess($parent)
 	{
-		$result     = array();
 		$user       = $this->application->getIdentity();
 		$language   = $this->application->getLanguage();
 
 		$noSeparator = true;
+		$children = $parent->getChildren();
+
+		/**
+		 * Trigger onPreprocessMenuItems for the current level of backend menu items.
+		 * $children is an array of MenuItem objects. A plugin can traverse the whole tree,
+		 * but new nodes will only be run through this method if their parents have not been processed yet.
+		 */
+		$this->application->triggerEvent('onPreprocessMenuItems', array('com_menus.administrator.module', $children, $this->params, $this->enabled));
 
-		// Call preprocess for the menu items on plugins.
-		// Plugins should normally process the current level only unless their logic needs deep levels too.
-		$this->application->triggerEvent('onPreprocessMenuItems', array('com_menus.administrator.module', &$items, $this->params, $this->enabled));
 
-		foreach ($items as $i => &$item)
+		foreach ($children as $item)
 		{
 			// Exclude item with menu item option set to exclude from menu modules
-			if ($item->params->get('menu_show', 1) == 0)
+			if ($item->getParams()->get('menu_show', 1) == 0)
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
@@ -285,6 +290,7 @@ protected function preprocess($items)
 			// Whether this scope can be displayed. Applies only to preset items. Db driven items should use un/published state.
 			if (($item->scope === 'help' && $this->params->get('showhelp', 1) == 0) || ($item->scope === 'edit' && !$this->params->get('shownew', 1)))
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
@@ -305,12 +311,14 @@ protected function preprocess($items)
 			// Exclude item if is not enabled
 			if ($item->element && !ComponentHelper::isEnabled($item->element))
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
 			// Exclude Mass Mail if disabled in global configuration
 			if ($item->scope === 'massmail' && ($this->application->get('massmailoff', 0) == 1))
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
@@ -336,6 +344,7 @@ protected function preprocess($items)
 
 				if (!$createFields)
 				{
+					$parent->removeChild($item);
 					continue;
 				}
 
@@ -355,6 +364,7 @@ protected function preprocess($items)
 
 				if (!$workflow)
 				{
+					$parent->removeChild($item);
 					continue;
 				}
 
@@ -362,6 +372,7 @@ protected function preprocess($items)
 			}
 			elseif ($item->element === 'com_config' && !$user->authorise('core.admin'))
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 			elseif ($item->element === 'com_admin')
@@ -370,23 +381,29 @@ protected function preprocess($items)
 
 				if (isset($query['view']) && $query['view'] === 'sysinfo' && !$user->authorise('core.admin'))
 				{
+					$parent->removeChild($item);
 					continue;
 				}
 			}
 
 			if ($assetName && !$user->authorise(($item->scope === 'edit') ? 'core.create' : 'core.manage', $assetName))
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
 			// Exclude if link is invalid
 			if (!in_array($item->type, array('separator', 'heading', 'container')) && trim($item->link) === '')
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
 			// Process any children if exists
-			$item->submenu = $this->preprocess($item->submenu);
+			if ($item->hasChildren())
+			{
+				$this->preprocess($item);
+			}
 
 			// Populate automatic children for container items
 			if ($item->type === 'container')
@@ -394,20 +411,32 @@ protected function preprocess($items)
 				$exclude    = (array) $item->params->get('hideitems') ?: array();
 				$components = MenusHelper::getMenuItems('main', false, $exclude);
 
-				$item->components = MenuHelper::createLevels($components);
-				$item->components = $this->preprocess($item->components);
-				$item->components = ArrayHelper::sortObjects($item->components, 'text', 1, false, true);
+				// We are adding the nodes first to preprocess them, then sort them and add them again.
+				foreach ($components->getChildren() as $c)
+				{
+					$item->addChild($c);
+				}
+
+				$this->preprocess($item);
+				$children = ArrayHelper::sortObjects($item->getChildren(), 'text', 1, false, true);
+
+				foreach ($children as $c)
+				{
+					$item->addChild($c);
+				}
 			}
 
 			// Exclude if there are no child items under heading or container
-			if (in_array($item->type, array('heading', 'container')) && empty($item->submenu) && empty($item->components))
+			if (in_array($item->type, array('heading', 'container')) && !$item->hasChildren() && empty($item->components))
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
 			// Exclude help menu item if set such in mod_menu
 			if ($this->params->get('showhelp', 1) == 0 && $item->link == 'index.php?option=com_cpanel&view=help')
 			{
+				$parent->removeChild($item);
 				continue;
 			}
 
@@ -416,6 +445,7 @@ protected function preprocess($items)
 			{
 				if ($noSeparator)
 				{
+					$parent->removeChild($item);
 					continue;
 				}
 
@@ -439,91 +469,70 @@ protected function preprocess($items)
 			}
 
 			$item->text = Text::_($item->title);
-
-			$result[$i] = $item;
 		}
 
 		// If last one was a separator remove it too.
-		if ($noSeparator && isset($i))
+		$last = end($parent->getChildren());
+
+		if ($last && $last->type === 'separator' && $last->getSibling(false) && $last->getSibling(false)->type === 'separator')
 		{
-			unset($result[$i]);
+			$parent->removeChild($last);
 		}
-
-		return $result;
 	}
 
 	/**
-	 * Load the menu items from a hierarchical list of items into the menu tree
+	 * Method to get the CSS class name for an icon identifier or create one if
+	 * a custom image path is passed as the identifier
 	 *
-	 * @param   \stdClass[]  $levels  Menu items as a hierarchical list format
+	 * @param   MenuItem  $node  Node to get icon data from
 	 *
-	 * @return  void
+	 * @return  string	CSS class name
 	 *
 	 * @since   3.8.0
 	 */
-	protected function populateTree($levels)
+	public function getIconClass($node)
 	{
-		foreach ($levels as $item)
-		{
-			$class = $this->enabled ? $item->class : 'disabled';
+		$identifier = $node->class;
 
-			if ($item->type === 'separator')
-			{
-				$this->tree->addChild(new Node\Separator($item->title));
-			}
-			elseif ($item->type === 'heading')
-			{
-				// We already excluded heading type menu item with no children.
-				$this->tree->addChild(new Node\Heading($item->title, $class, null, $item->icon), $this->enabled);
+		// Top level is special
+		if (trim($identifier) == '')
+		{
+			return null;
+		}
 
-				if ($this->enabled)
-				{
-					$this->populateTree($item->submenu);
-					$this->tree->getParent();
-				}
-			}
-			elseif ($item->type === 'url')
+		// We were passed a class name
+		if (substr($identifier, 0, 6) == 'class:')
+		{
+			$class = substr($identifier, 6);
+		}
+		// We were passed background icon url. Build the CSS class for the icon
+		else
+		{
+			if ($identifier == null)
 			{
-				$cNode = new Node\Url($item->title, $item->link, $item->browserNav, $class, null, $item->icon);
-				$this->tree->addChild($cNode, $this->enabled);
-
-				if ($this->enabled)
-				{
-					$this->populateTree($item->submenu);
-					$this->tree->getParent();
-				}
+				return null;
 			}
-			elseif ($item->type === 'component')
-			{
-				$cNode = new Node\Component($item->title, $item->element, $item->link, $item->browserNav, $class, null, $item->icon);
-				$this->tree->addChild($cNode, $this->enabled);
 
-				if ($this->enabled)
-				{
-					$this->populateTree($item->submenu);
-					$this->tree->getParent();
-				}
-			}
-			elseif ($item->type === 'container')
-			{
-				// We already excluded container type menu item with no children.
-				$this->tree->addChild(new Node\Container($item->title, $item->class, null, $item->icon), $this->enabled);
+			$class = preg_replace('#\.[^.]*$#', '', basename($identifier));
+			$class = preg_replace('#\.\.[^A-Za-z0-9\.\_\- ]#', '', $class);
+		}
 
-				if ($this->enabled)
-				{
-					$this->populateTree($item->submenu);
+		$html = 'fa-fw fa fa-' . $class;
 
-					// Add a separator between dynamic menu items and components menu items
-					if (count($item->submenu) && count($item->components))
-					{
-						$this->tree->addChild(new Node\Separator);
-					}
+		return $html;
+	}
 
-					$this->populateTree($item->components);
+	/**
+	 * Create unique identifier
+	 *
+	 * @return  string
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getCounter()
+	{
+		$this->counter++;
 
-					$this->tree->getParent();
-				}
-			}
-		}
+		return $this->counter;
 	}
 }
diff --git a/administrator/modules/mod_menu/Menu/MenuNode.php b/administrator/modules/mod_menu/Menu/MenuNode.php
deleted file mode 100644
index 8ee4c2f9b852a..0000000000000
--- a/administrator/modules/mod_menu/Menu/MenuNode.php
+++ /dev/null
@@ -1,196 +0,0 @@
-<?php
-/**
- * @package     Joomla.Administrator
- * @subpackage  mod_menu
- *
- * @copyright   Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license     GNU General Public License version 2 or later; see LICENSE.txt
- */
-
-namespace Joomla\Module\Menu\Administrator\Menu;
-
-defined('_JEXEC') or die;
-
-use Joomla\CMS\Uri\Uri;
-use Joomla\Filter\OutputFilter;
-
-/**
- * A Node for JAdminCssMenu
- *
- * @see    JAdminCssMenu
- * @since  1.5
- */
-class MenuNode
-{
-	/**
-	 * Node Title
-	 *
-	 * @var  string
-	 */
-	public $title = null;
-
-	/**
-	 * Node Id
-	 *
-	 * @var  string
-	 */
-	public $id = null;
-
-	/**
-	 * Node Link
-	 *
-	 * @var  string
-	 */
-	public $link = null;
-
-	/**
-	 * Link Target
-	 *
-	 * @var  string
-	 */
-	public $target = null;
-
-	/**
-	 * CSS Class for node
-	 *
-	 * @var  string
-	 */
-	public $class = null;
-
-	/**
-	 * Active Node?
-	 *
-	 * @var  boolean
-	 */
-	public $active = false;
-
-	/**
-	 * Parent node
-	 *
-	 * @var  MenuNode
-	 */
-	protected $_parent = null;
-
-	/**
-	 * Array of Children
-	 *
-	 * @var  array
-	 */
-	protected $_children = array();
-
-	/**
-	 * Constructor for the class.
-	 *
-	 * @param   string   $title      The title of the node
-	 * @param   string   $link       The node link
-	 * @param   string   $class      The CSS class for the node
-	 * @param   boolean  $active     True if node is active, false otherwise
-	 * @param   string   $target     The link target
-	 * @param   string   $titleicon  The title icon for the node
-	 */
-	public function __construct($title, $link = null, $class = null, $active = false, $target = null, $titleicon = null)
-	{
-		$this->title  = $titleicon ? $title . $titleicon : $title;
-		$this->link   = OutputFilter::ampReplace($link);
-		$this->class  = $class;
-		$this->active = $active;
-
-		$this->id = null;
-
-		if (!empty($link) && $link !== '#')
-		{
-			$uri    = new Uri($link);
-			$params = $uri->getQuery(true);
-			$parts  = array();
-
-			foreach ($params as $value)
-			{
-				$parts[] = str_replace(array('.', '_'), '-', $value);
-			}
-
-			$this->id = implode('-', $parts);
-		}
-
-		$this->target = $target;
-	}
-
-	/**
-	 * Add child to this node
-	 *
-	 * If the child already has a parent, the link is unset
-	 *
-	 * @param   MenuNode  &$child  The child to be added
-	 *
-	 * @return  void
-	 */
-	public function addChild(MenuNode &$child)
-	{
-		$child->setParent($this);
-	}
-
-	/**
-	 * Set the parent of a this node
-	 *
-	 * If the node already has a parent, the link is unset
-	 *
-	 * @param   JMenuNode  &$parent  The JMenuNode for parent to be set or null
-	 *
-	 * @return  void
-	 */
-	public function setParent(MenuNode &$parent = null)
-	{
-		$hash = spl_object_hash($this);
-
-		if (!is_null($this->_parent))
-		{
-			unset($this->_parent->_children[$hash]);
-		}
-
-		if (!is_null($parent))
-		{
-			$parent->_children[$hash] = &$this;
-		}
-
-		$this->_parent = &$parent;
-	}
-
-	/**
-	 * Get the children of this node
-	 *
-	 * @return  array  The children
-	 */
-	public function &getChildren()
-	{
-		return $this->_children;
-	}
-
-	/**
-	 * Get the parent of this node
-	 *
-	 * @return  mixed  JMenuNode object with the parent or null for no parent
-	 */
-	public function &getParent()
-	{
-		return $this->_parent;
-	}
-
-	/**
-	 * Test if this node has children
-	 *
-	 * @return  boolean  True if there are children
-	 */
-	public function hasChildren()
-	{
-		return (bool) count($this->_children);
-	}
-
-	/**
-	 * Test if this node has a parent
-	 *
-	 * @return  boolean  True if there is a parent
-	 */
-	public function hasParent()
-	{
-		return $this->getParent() != null;
-	}
-}
diff --git a/administrator/modules/mod_menu/mod_menu.php b/administrator/modules/mod_menu/mod_menu.php
index 0cff6213d70a9..67a7f818f4046 100644
--- a/administrator/modules/mod_menu/mod_menu.php
+++ b/administrator/modules/mod_menu/mod_menu.php
@@ -15,7 +15,8 @@
 $enabled = !$app->input->getBool('hidemainmenu');
 
 $menu = new CssMenu($app);
-$menu->load($params, $enabled);
+$root = $menu->load($params, $enabled);
+$root->level = 0;
 
 // Render the module layout
 require ModuleHelper::getLayoutPath('mod_menu', $params->get('layout', 'default'));
diff --git a/administrator/modules/mod_menu/tmpl/default.php b/administrator/modules/mod_menu/tmpl/default.php
index 36fc41cec214f..3e4b5290b1f5a 100644
--- a/administrator/modules/mod_menu/tmpl/default.php
+++ b/administrator/modules/mod_menu/tmpl/default.php
@@ -21,9 +21,6 @@
 $class     = $enabled ? 'nav flex-column main-nav ' . $direction : 'nav flex-column main-nav disabled ' . $direction;
 
 // Recurse through children of root node if they exist
-$menuTree = $menu->getTree();
-$root     = $menuTree->reset();
-
 if ($root->hasChildren())
 {
 	echo '<nav class="main-nav-container" aria-label="' . Text::_('MOD_MENU_ARIA_MAIN_MENU') . '">';
@@ -36,12 +33,7 @@
 	echo '</li>';
 
 	// WARNING: Do not use direct 'include' or 'require' as it is important to isolate the scope for each call
-	$menu->renderSubmenu(ModuleHelper::getLayoutPath('mod_menu', 'default_submenu'));
+	$menu->renderSubmenu(ModuleHelper::getLayoutPath('mod_menu', 'default_submenu'), $root);
 
 	echo "</ul></nav>\n";
-
-	if ($css = $menuTree->getCss())
-	{
-		$doc->addStyleDeclaration(implode("\n", $css));
-	}
 }
diff --git a/administrator/modules/mod_menu/tmpl/default_submenu.php b/administrator/modules/mod_menu/tmpl/default_submenu.php
index e9496e370cdf6..0b00984d64efa 100644
--- a/administrator/modules/mod_menu/tmpl/default_submenu.php
+++ b/administrator/modules/mod_menu/tmpl/default_submenu.php
@@ -10,7 +10,6 @@
 defined('_JEXEC') or die;
 
 use Joomla\CMS\Language\Text;
-use Joomla\CMS\Menu\Node\Separator;
 
 /**
  * =========================================================================================================
@@ -19,7 +18,6 @@
  * =========================================================================================================
  */
 /** @var  \Joomla\Module\Menu\Administrator\Menu\CssMenu  $this */
-$current = $this->tree->getCurrent();
 $class   = '';
 
 // Build the CSS class suffix
@@ -27,15 +25,15 @@
 {
 	$class = ' class="disabled"';
 }
-elseif ($current instanceOf Separator)
+elseif ($current->type == 'separator')
 {
-	$class = $current->get('title') ? ' class="menuitem-group"' : ' class="divider"';
+	$class = $current->title ? ' class="menuitem-group"' : ' class="divider"';
 }
 elseif ($current->hasChildren())
 {
 	$class = ' class="dropdown-submenu"';
 
-	if ($current->getLevel() == 1)
+	if ($current->level == 1)
 	{
 		$class = ' class="parent"';
 	}
@@ -46,7 +44,7 @@
 }
 
 // Set the correct aria role and print the item
-if ($current instanceOf Separator)
+if ($current->type == 'separator')
 {
 	echo '<li' . $class . ' role="presentation">';
 }
@@ -64,7 +62,7 @@
 {
 	$linkClass[] = 'has-arrow';
 
-	if ($current->getLevel() > 2)
+	if ($current->level > 2)
 	{
 		$dataToggle  = ' data-toggle="dropdown"';
 	}
@@ -81,22 +79,22 @@
 $link      = $current->get('link');
 
 // Get the menu icon
-$icon      = $this->tree->getIconClass();
-$iconClass = ($icon != '' && $current->getLevel() == 1) ? '<span class="' . $icon . '" aria-hidden="true"></span>' : '';
+$icon      = $this->getIconClass($current);
+$iconClass = ($icon != '' && $current->level == 1) ? '<span class="' . $icon . '" aria-hidden="true"></span>' : '';
 
-if ($link !== null && $current->get('target') !== null && $current->get('target') !== '')
+if ($link != '' && $current->target != '')
 {
-	echo "<a" . $linkClass . $dataToggle . " href=\"" . $link . "\" target=\"" . $current->get('target') . "\">"
+	echo "<a" . $linkClass . $dataToggle . " href=\"" . $link . "\" target=\"" . $current->target . "\">"
 		. $iconClass
-		. '<span class="sidebar-item-title">' . Text::_($current->get('title')) . "</span></a>";
+		. '<span class="sidebar-item-title">' . Text::_($current->title) . "</span></a>";
 }
-elseif ($link !== null)
+elseif ($link != '')
 {
 	echo "<a" . $linkClass . $dataToggle . " href=\"" . $link . "\">"
 		. $iconClass
 		. '<span class="sidebar-item-title">' . Text::_($current->get('title')) . "</span></a>";
 }
-elseif ($current->get('title') !== null && $current->get('class') !== 'separator')
+elseif ($current->title != '' && $current->get('class') !== 'separator')
 {
 	echo "<a" . $linkClass . $dataToggle . ">"
 		. $iconClass
@@ -110,19 +108,19 @@
 // Recurse through children if they exist
 if ($this->enabled && $current->hasChildren())
 {
-	if ($current->getLevel() > 1)
+	if ($current->level > 1)
 	{
 		$id = $current->get('id') ? ' id="menu-' . strtolower($current->get('id')) . '"' : '';
 
-		echo '<ul' . $id . ' class="collapse collapse-level-' . $current->getLevel() . '">' . "\n";
+		echo '<ul' . $id . ' class="collapse collapse-level-' . $current->level . '">' . "\n";
 	}
 	else
 	{
-		echo '<ul id="collapse' . $this->tree->getCounter() . '" class="collapse-level-1 collapse" role="menu" aria-haspopup="true">' . "\n";
+		echo '<ul id="collapse' . $this->getCounter() . '" class="collapse-level-1 collapse" role="menu" aria-haspopup="true">' . "\n";
 	}
 
 	// WARNING: Do not use direct 'include' or 'require' as it is important to isolate the scope for each call
-	$this->renderSubmenu(__FILE__);
+	$this->renderSubmenu(__FILE__, $current);
 
 	echo "</ul>\n";
 }
diff --git a/administrator/templates/atum/scss/vendor/bootstrap/_table.scss b/administrator/templates/atum/scss/vendor/bootstrap/_table.scss
index cd5c68fbafc7a..947b62d22ce50 100644
--- a/administrator/templates/atum/scss/vendor/bootstrap/_table.scss
+++ b/administrator/templates/atum/scss/vendor/bootstrap/_table.scss
@@ -8,7 +8,6 @@
       font-weight: $normal-weight;
       color: $gray-800;
       white-space: nowrap;
-      border-bottom: 2px solid $gray-300;
     }
     td {
       padding: 0;
diff --git a/build/media_source/system/css/fields/calendar-rtl.css b/build/media_source/system/css/fields/calendar-rtl.css
index 4635b51246088..113c593842a72 100644
--- a/build/media_source/system/css/fields/calendar-rtl.css
+++ b/build/media_source/system/css/fields/calendar-rtl.css
@@ -32,6 +32,10 @@ div.calendar-container table body td {
 	line-height: 2em;
 }
 
+.calendar-container table {
+	border-collapse: separate;
+}
+
 div.calendar-container table td.title { /* This holds the current "month, year" */
 	vertical-align: middle;
 	text-align: center;
@@ -150,7 +154,7 @@ a.js-btn.btn.btn-exit, a.js-btn.btn.btn-today, a.js-btn.btn.btn-clear {
 	padding: 8px 8px 8px 0;
 }
 .time .time-title {
-	background-image: url("data:image/png;base64, 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");
+	background-image: url("data:image/svg+xml,%3C%3Fxml version='1.0' encoding='utf-8'%3F%3E%3Csvg width='22' height='22' viewBox='0 0 1792 1792' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1024 544v448q0 14-9 23t-23 9h-320q-14 0-23-9t-9-23v-64q0-14 9-23t23-9h224v-352q0-14 9-23t23-9h64q14 0 23 9t9 23zm416 352q0-148-73-273t-198-198-273-73-273 73-198 198-73 273 73 273 198 198 273 73 273-73 198-198 73-273zm224 0q0 209-103 385.5t-279.5 279.5-385.5 103-385.5-103-279.5-279.5-103-385.5 103-385.5 279.5-279.5 385.5-103 385.5 103 279.5 279.5 103 385.5z'/%3E%3C/svg%3E");
 	background-repeat: no-repeat;
 	background-position: center;
 }
diff --git a/build/media_source/system/css/fields/calendar.css b/build/media_source/system/css/fields/calendar.css
index 782c930aa1673..16e827457cf9d 100644
--- a/build/media_source/system/css/fields/calendar.css
+++ b/build/media_source/system/css/fields/calendar.css
@@ -32,6 +32,10 @@ div.calendar-container table body td {
 	line-height: 2em;
 }
 
+.calendar-container table {
+	border-collapse: separate;
+}
+
 div.calendar-container table td.title { /* This holds the current "month, year" */
 	vertical-align: middle;
 	text-align: center;
@@ -149,7 +153,7 @@ a.js-btn.btn.btn-exit, a.js-btn.btn.btn-today, a.js-btn.btn.btn-clear {
 	padding: 8px 0 8px 8px;
 }
 .time .time-title {
-	background-image: url("data:image/png;base64, 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");
+	background-image: url("data:image/svg+xml,%3C%3Fxml version='1.0' encoding='utf-8'%3F%3E%3Csvg width='22' height='22' viewBox='0 0 1792 1792' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1024 544v448q0 14-9 23t-23 9h-320q-14 0-23-9t-9-23v-64q0-14 9-23t23-9h224v-352q0-14 9-23t23-9h64q14 0 23 9t9 23zm416 352q0-148-73-273t-198-198-273-73-273 73-198 198-73 273 73 273 198 198 273 73 273-73 198-198 73-273zm224 0q0 209-103 385.5t-279.5 279.5-385.5 103-385.5-103-279.5-279.5-103-385.5 103-385.5 279.5-279.5 385.5-103 385.5 103 279.5 279.5 103 385.5z'/%3E%3C/svg%3E");
 	background-repeat: no-repeat;
 	background-position: center;
 }
diff --git a/build/media_source/system/js/fields/joomla-field-fancy-select.w-c.es6.js b/build/media_source/system/js/fields/joomla-field-fancy-select.w-c.es6.js
index 3e54bf28a61a5..91654019ac426 100644
--- a/build/media_source/system/js/fields/joomla-field-fancy-select.w-c.es6.js
+++ b/build/media_source/system/js/fields/joomla-field-fancy-select.w-c.es6.js
@@ -24,164 +24,186 @@
  * placeholder=""        The value of the inputs placeholder.
  * search-placeholder="" The value of the search inputs placeholder.
  */
-(function (customElements) {
-  'use strict';
+window.customElements.define('joomla-field-fancy-select', class extends HTMLElement {
+  // Attributes to monitor
+  get allowCustom() { return this.hasAttribute('allow-custom'); }
 
-  class JoomlaFieldFancySelect extends HTMLElement {
-    // Properties getters/setters
-    get allowCustom() { return this.hasAttribute('allow-custom'); }
+  get remoteSearch() { return this.hasAttribute('remote-search'); }
 
-    get remoteSearch() { return this.hasAttribute('remote-search'); }
+  get url() { return this.getAttribute('url'); }
 
-    get url() { return this.getAttribute('url'); }
+  get termKey() { return this.getAttribute('term-key') || 'term'; }
 
-    get termKey() { return this.getAttribute('term-key') || 'term'; }
+  get minTermLength() { return parseInt(this.getAttribute('min-term-length')) || 1; }
 
-    get minTermLength() { return parseInt(this.getAttribute('min-term-length')) || 1; }
+  get newItemPrefix() { return this.getAttribute('new-item-prefix') || ''; }
 
-    get newItemPrefix() { return this.getAttribute('new-item-prefix') || ''; }
+  get placeholder() { return this.getAttribute('placeholder'); }
 
-    get placeholder() { return this.getAttribute('placeholder'); }
+  get searchPlaceholder() { return this.getAttribute('search-placeholder'); }
 
-    get searchPlaceholder() { return this.getAttribute('search-placeholder'); }
+  get value() {return this.choicesInstance.getValue(true); }
 
-    get value() { return this.choicesInstance.getValue(true); }
+  set value($val) { this.choicesInstance.setValueByChoice($val); }
 
-    set value($val) { this.choicesInstance.setValueByChoice(`${$val}`); }
+  /**
+   * Lifecycle
+   */
+  constructor() {
+    super();
 
-    connectedCallback() {
-      if (!window.Choices) {
-        throw new Error('JoomlaFieldFancySelect require Choices.js to work');
-      }
-
-      // Get a <select> element
-      this.select = this.querySelector('select');
+    // Keycodes
+    this.keyCode = {
+      ENTER: 13,
+    };
 
-      if (!this.select) {
-        throw new Error('JoomlaFieldFancySelect require <select> element to work');
-      }
-
-      // Init Choices
-      this.choicesInstance = new Choices(this.select, {
-        placeholderValue: this.placeholder,
-        searchPlaceholderValue: this.searchPlaceholder,
-        removeItemButton: true,
-        searchFloor: this.minTermLength,
-        searchResultLimit: 10,
-        shouldSort: false,
-        fuseOptions: {
-          threshold: 0.3, // Strict search
-        },
-        noResultsText: Joomla.Text._('JGLOBAL_SELECT_NO_RESULTS_MATCH', 'No results found'),
-        noChoicesText: Joomla.Text._('JGLOBAL_SELECT_NO_RESULTS_MATCH', 'No results found'),
-        itemSelectText: Joomla.Text._('JGLOBAL_SELECT_PRESS_TO_SELECT', 'Press to select'),
-
-        // Redefine some classes
-        classNames: {
-          button: 'choices__button_joomla', // It is need because an original styling use unavailable Icon.svg file
-        },
-      });
+    if (!Joomla) {
+      throw new Error('Joomla API is not properly initiated');
+    }
 
-      // Collect an existing values, to avoid duplications
-      this.choicesCache = {};
+    if (!window.Choices) {
+      throw new Error('JoomlaFieldFancySelect requires Choices.js to work');
+    }
 
-      // Handle typing of custom term
-      if (this.allowCustom) {
-        this.addEventListener('keydown', (event) => {
-          if (event.keyCode !== 13 || event.target !== this.choicesInstance.input) return;
-          event.preventDefault();
+    this.choicesCache = {};
+    this.activeXHR = null;
+    this.choicesInstance = null;
+  }
 
-          if (this.choicesInstance.highlightPosition
-            || !event.target.value || this.choicesCache[event.target.value]) return;
+  /**
+   * Lifecycle
+   */
+  connectedCallback() {
+    // Get a <select> element
+    this.select = this.querySelector('select');
 
-          // Make sure nothing is highlighted
-          const highlighted = this.choicesInstance.dropdown.querySelector(`.${this.choicesInstance.config.classNames.highlightedState}`);
-          if (highlighted) return;
+    if (!this.select) {
+      throw new Error('JoomlaFieldFancySelect requires <select> element to work');
+    }
 
-          this.choicesInstance.setChoices([{
-            value: this.newItemPrefix + event.target.value,
-            label: event.target.value,
-            selected: true,
-            customProperties: {
-              value: event.target.value, // Store real value, just in case
-            },
-          }], 'value', 'label', false);
+    // Init Choices
+    this.choicesInstance = new Choices(this.select, {
+      placeholderValue: this.placeholder,
+      searchPlaceholderValue: this.searchPlaceholder,
+      removeItemButton: true,
+      searchFloor: this.minTermLength,
+      searchResultLimit: 10,
+      shouldSort: false,
+      fuseOptions: {
+        threshold: 0.3 // Strict search
+      },
+      noResultsText: Joomla.Text._('JGLOBAL_SELECT_NO_RESULTS_MATCH', 'No results found'),
+      noChoicesText: Joomla.Text._('JGLOBAL_SELECT_NO_RESULTS_MATCH', 'No results found'),
+      itemSelectText: Joomla.Text._('JGLOBAL_SELECT_PRESS_TO_SELECT', 'Press to select'),
+
+      // Redefine some classes
+      classNames: {
+        button: 'choices__button_joomla' // It is need because an original styling use unavailable Icon.svg file
+      }
+    });
+
+    // Handle typing of custom term
+    if (this.allowCustom) {
+      this.addEventListener('keydown', (event) => {
+        if (event.keyCode !== this.keyCode.ENTER || event.target !== this.choicesInstance.input) {
+          return;
+        }
+        event.preventDefault();
+
+        if (this.choicesInstance.highlightPosition || !event.target.value || this.choicesCache[event.target.value]) {
+          return;
+        }
+
+        // Make sure nothing is highlighted
+        const highlighted = this.choicesInstance.dropdown.querySelector(`.${this.choicesInstance.config.classNames.highlightedState}`);
+        if (highlighted) {
+          return;
+        };
+
+        this.choicesInstance.setChoices([{
+          value: this.newItemPrefix + event.target.value,
+          label: event.target.value,
+          selected: true,
+          customProperties: {
+            value: event.target.value // Store real value, just in case
+          }
+        }], 'value', 'label', false);
 
-          this.choicesCache[event.target.value] = event.target.value;
+        this.choicesCache[event.target.value] = event.target.value;
 
-          event.target.value = null;
-          this.choicesInstance.hideDropdown();
+        event.target.value = null;
+        this.choicesInstance.hideDropdown();
 
-          return false;
-        });
-      }
+        return false;
+      });
+    }
 
-      // Handle remote search
-      if (this.remoteSearch && this.url) {
-        // Cache existing
-        this.choicesInstance.presetChoices.forEach((choiceItem) => {
-          this.choicesCache[choiceItem.value] = choiceItem.label;
-        });
+    // Handle remote search
+    if (this.remoteSearch && this.url) {
+      // Cache existing
+      this.choicesInstance.presetChoices.forEach((choiceItem) => {
+        this.choicesCache[choiceItem.value] = choiceItem.label;
+      });
 
-        const lookupDelay = 300;
-        let lookupTimeout = null;
-        this.activeXHR = null;
-        this.select.addEventListener('search', (event) => {
-          clearTimeout(lookupTimeout);
-          lookupTimeout = setTimeout(this.requestLookup.bind(this), lookupDelay);
-        });
-      }
+      const lookupDelay = 300;
+      let lookupTimeout = null;
+      this.select.addEventListener('search', (event) => {
+        clearTimeout(lookupTimeout);
+        lookupTimeout = setTimeout(this.requestLookup.bind(this), lookupDelay);
+      });
     }
+  }
 
-    disconnectedCallback() {
-      // Destroy Choices instance, to unbind an event listeners
-      if (this.choicesInstance) {
-        this.choicesInstance.destroy();
-        this.choicesInstance = null;
-      }
-      if (this.activeXHR) {
-        this.activeXHR.abort();
-        this.activeXHR = null;
-      }
+  /**
+   * Lifecycle
+   */
+  disconnectedCallback() {
+    // Destroy Choices instance, to unbind event listeners
+    if (this.choicesInstance) {
+      this.choicesInstance.destroy();
+      this.choicesInstance = null;
     }
+    if (this.activeXHR) {
+      this.activeXHR.abort();
+      this.activeXHR = null;
+    }
+  }
 
-    requestLookup() {
-      let url = this.url;
-      url += (url.indexOf('?') === -1 ? '?' : '&');
-      url += `${encodeURIComponent(this.termKey)}=${encodeURIComponent(this.choicesInstance.input.value)}`;
+  requestLookup() {
+    let url = this.url;
+    url += (url.indexOf('?') === -1 ? '?' : '&');
+    url += `${encodeURIComponent(this.termKey)}=${encodeURIComponent(this.choicesInstance.input.value)}`;
 
-      // Stop previous request if any
-      if (this.activeXHR) {
-        this.activeXHR.abort();
-      }
+    // Stop previous request if any
+    if (this.activeXHR) {
+      this.activeXHR.abort();
+    }
 
-      this.activeXHR = Joomla.request({
-        url,
-        onSuccess: (response, xhr) => {
-          this.activeXHR = null;
-          const items = response ? JSON.parse(response) : [];
-          if (!items.length) return;
-
-          // Remove duplications
-          let item;
-          for (let i = items.length - 1; i >= 0; i--) {
-            item = items[i];
-            if (this.choicesCache[item.value]) {
-              items.splice(i, 1);
-            }
+    this.activeXHR = Joomla.request({
+      url: url,
+      onSuccess: (response) => {
+        this.activeXHR = null;
+        const items = response ? JSON.parse(response) : [];
+        if (!items.length) {
+          return;
+        }
+
+        // Remove duplications
+        items.forEach((item, index) => {
+          if (this.choicesCache[item.value]) {
+            items.splice(index, 1);
           }
+        });
 
-          // Add new options to field, assume that each item is object, eg {value: "foo", text: "bar"}
-          if (items.length) {
-            this.choicesInstance.setChoices(items, 'value', 'text', false);
-          }
-        },
-        onError: () => {
-          this.activeXHR = null;
-        },
-      });
-    }
+        // Add new options to field, assume that each item is object, eg {value: "foo", text: "bar"}
+        if (items.length) {
+          this.choicesInstance.setChoices(items, 'value', 'text', false);
+        }
+      },
+      onError: () => {
+        this.activeXHR = null;
+      }
+    });
   }
 
-  customElements.define('joomla-field-fancy-select', JoomlaFieldFancySelect);
-}(customElements));
+});
diff --git a/libraries/src/Categories/CategoryNode.php b/libraries/src/Categories/CategoryNode.php
index 7d1c4d8c6d474..c81b24dd7e8d1 100644
--- a/libraries/src/Categories/CategoryNode.php
+++ b/libraries/src/Categories/CategoryNode.php
@@ -12,6 +12,8 @@
 
 use Joomla\CMS\Factory;
 use Joomla\CMS\Object\CMSObject;
+use Joomla\CMS\Tree\NodeInterface;
+use Joomla\CMS\Tree\NodeTrait;
 use Joomla\Registry\Registry;
 
 /**
@@ -19,8 +21,10 @@
  *
  * @since  1.6
  */
-class CategoryNode extends CMSObject
+class CategoryNode extends CMSObject implements NodeInterface
 {
+	use NodeTrait;
+
 	/**
 	 * Primary key
 	 *
@@ -245,22 +249,6 @@ class CategoryNode extends CMSObject
 	 */
 	public $assets = null;
 
-	/**
-	 * Parent Category object
-	 *
-	 * @var    CategoryNode
-	 * @since  1.6
-	 */
-	protected $_parent = null;
-
-	/**
-	 * Array of Children
-	 *
-	 * @var    CategoryNode[]
-	 * @since  1.6
-	 */
-	protected $_children = array();
-
 	/**
 	 * Path from root to this category
 	 *
@@ -269,22 +257,6 @@ class CategoryNode extends CMSObject
 	 */
 	protected $_path = array();
 
-	/**
-	 * Category left of this one
-	 *
-	 * @var    CategoryNode
-	 * @since  1.6
-	 */
-	protected $_leftSibling = null;
-
-	/**
-	 * Category right of this one
-	 *
-	 * @var    CategoryNode
-	 * @since  1.6
-	 */
-	protected $_rightSibling = null;
-
 	/**
 	 * Flag if all children have been loaded
 	 *
@@ -296,7 +268,7 @@ class CategoryNode extends CMSObject
 	/**
 	 * Constructor of this tree
 	 *
-	 * @var    CategoryNode
+	 * @var    Categories
 	 * @since  1.6
 	 */
 	protected $_constructor = null;
@@ -304,8 +276,8 @@ class CategoryNode extends CMSObject
 	/**
 	 * Class constructor
 	 *
-	 * @param   array         $category     The category data.
-	 * @param   CategoryNode  $constructor  The tree constructor.
+	 * @param   array       $category     The category data.
+	 * @param   Categories  $constructor  The tree constructor.
 	 *
 	 * @since   1.6
 	 */
@@ -337,74 +309,31 @@ public function __construct($category = null, $constructor = null)
 	 *
 	 * @since   1.6
 	 */
-	public function setParent($parent)
+	public function setParent(NodeInterface $parent)
 	{
-		if ($parent instanceof CategoryNode || is_null($parent))
+		if (!is_null($this->_parent))
 		{
-			if (!is_null($this->_parent))
-			{
-				$key = array_search($this, $this->_parent->_children);
-				unset($this->_parent->_children[$key]);
-			}
-
-			if (!is_null($parent))
-			{
-				$parent->_children[] = & $this;
-			}
-
-			$this->_parent = $parent;
+			$key = array_search($this, $this->_parent->_children);
+			unset($this->_parent->_children[$key]);
+		}
 
-			if ($this->id != 'root')
-			{
-				if ($this->parent_id != 1)
-				{
-					$this->_path = $parent->getPath();
-				}
+		$this->_parent = $parent;
 
-				$this->_path[$this->id] = $this->id . ':' . $this->alias;
-			}
+		$this->_parent->_children[] = & $this;
 
-			if (count($parent->_children) > 1)
-			{
-				end($parent->_children);
-				$this->_leftSibling = prev($parent->_children);
-				$this->_leftSibling->_rightsibling = & $this;
-			}
+		if (count($this->_parent->_children) > 1)
+		{
+			end($this->_parent->_children);
+			$this->_leftSibling = prev($this->_parent->_children);
+			$this->_leftSibling->_rightsibling = & $this;
 		}
-	}
 
-	/**
-	 * Add child to this node
-	 *
-	 * If the child already has a parent, the link is unset
-	 *
-	 * @param   CategoryNode  $child  The child to be added.
-	 *
-	 * @return  void
-	 *
-	 * @since   1.6
-	 */
-	public function addChild($child)
-	{
-		if ($child instanceof CategoryNode)
+		if ($this->parent_id != 1)
 		{
-			$child->setParent($this);
+			$this->_path = $parent->getPath();
 		}
-	}
 
-	/**
-	 * Remove a specific child
-	 *
-	 * @param   integer  $id  ID of a category
-	 *
-	 * @return  void
-	 *
-	 * @since   1.6
-	 */
-	public function removeChild($id)
-	{
-		$key = array_search($this, $this->_parent->_children);
-		unset($this->_parent->_children[$key]);
+		$this->_path[$this->id] = $this->id . ':' . $this->alias;
 	}
 
 	/**
@@ -447,64 +376,6 @@ public function &getChildren($recursive = false)
 		return $this->_children;
 	}
 
-	/**
-	 * Get the parent of this node
-	 *
-	 * @return  CategoryNode
-	 *
-	 * @since   1.6
-	 */
-	public function getParent()
-	{
-		return $this->_parent;
-	}
-
-	/**
-	 * Test if this node has children
-	 *
-	 * @return  boolean  True if there is a child
-	 *
-	 * @since   1.6
-	 */
-	public function hasChildren()
-	{
-		return count($this->_children);
-	}
-
-	/**
-	 * Test if this node has a parent
-	 *
-	 * @return  boolean  True if there is a parent
-	 *
-	 * @since   1.6
-	 */
-	public function hasParent()
-	{
-		return $this->getParent() != null;
-	}
-
-	/**
-	 * Function to set the left or right sibling of a category
-	 *
-	 * @param   CategoryNode  $sibling  CategoryNode object for the sibling
-	 * @param   boolean       $right    If set to false, the sibling is the left one
-	 *
-	 * @return  void
-	 *
-	 * @since   1.6
-	 */
-	public function setSibling($sibling, $right = true)
-	{
-		if ($right)
-		{
-			$this->_rightSibling = $sibling;
-		}
-		else
-		{
-			$this->_leftSibling = $sibling;
-		}
-	}
-
 	/**
 	 * Returns the right or left sibling of a category
 	 *
diff --git a/libraries/src/Menu/MenuHelper.php b/libraries/src/Menu/MenuHelper.php
deleted file mode 100644
index 489e02a9f1fca..0000000000000
--- a/libraries/src/Menu/MenuHelper.php
+++ /dev/null
@@ -1,388 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu;
-
-defined('JPATH_PLATFORM') or die;
-
-use Joomla\CMS\Factory;
-use Joomla\CMS\Filesystem\Folder;
-use Joomla\Registry\Registry;
-
-/**
- * Menu Helper utility
- *
- * @since  3.8.0
- */
-class MenuHelper
-{
-	/**
-	 * List of preset include paths
-	 *
-	 * @var  array
-	 *
-	 * @since   3.8.0
-	 */
-	protected static $presets = null;
-
-	/**
-	 * Private constructor
-	 *
-	 * @since   3.8.0
-	 */
-	private function __construct()
-	{
-	}
-
-	/**
-	 * Add a custom preset externally via plugin or any other means.
-	 * WARNING: Presets with same name will replace previously added preset *except* Joomla's default preset (joomla)
-	 *
-	 * @param   string  $name     The unique identifier for the preset.
-	 * @param   string  $title    The display label for the preset.
-	 * @param   string  $path     The path to the preset file.
-	 * @param   bool    $replace  Whether to replace the preset with the same name if any (except 'joomla').
-	 *
-	 * @return  void
-	 *
-	 * @since   3.8.0
-	 */
-	public static function addPreset($name, $title, $path, $replace = true)
-	{
-		if (static::$presets === null)
-		{
-			static::getPresets();
-		}
-
-		if ($name == 'joomla')
-		{
-			$replace = false;
-		}
-
-		if (($replace || !array_key_exists($name, static::$presets)) && is_file($path))
-		{
-			$preset = new \stdClass;
-
-			$preset->name  = $name;
-			$preset->title = $title;
-			$preset->path  = $path;
-
-			static::$presets[$name] = $preset;
-		}
-	}
-
-	/**
-	 * Get a list of available presets.
-	 *
-	 * @return  \stdClass[]
-	 *
-	 * @since   3.8.0
-	 */
-	public static function getPresets()
-	{
-		if (static::$presets === null)
-		{
-			// Important: 'null' will cause infinite recursion.
-			static::$presets = array();
-
-			static::addPreset('joomla', 'JLIB_MENUS_PRESET_JOOMLA', JPATH_ADMINISTRATOR . '/components/com_menus/presets/joomla.xml');
-			static::addPreset('modern', 'JLIB_MENUS_PRESET_MODERN', JPATH_ADMINISTRATOR . '/components/com_menus/presets/modern.xml');
-
-			// Load from template folder automatically
-			$app = Factory::getApplication();
-			$tpl = JPATH_THEMES . '/' . $app->getTemplate() . '/html/com_menus/presets';
-
-			if (is_dir($tpl))
-			{
-				$files = Folder::files($tpl, '\.xml$');
-
-				foreach ($files as $file)
-				{
-					$name  = substr($file, 0, -4);
-					$title = str_replace('-', ' ', $name);
-
-					static::addPreset(strtolower($name), ucwords($title), $tpl . '/' . $file);
-				}
-			}
-		}
-
-		return static::$presets;
-	}
-
-	/**
-	 * Load the menu items from a preset file into a hierarchical list of objects
-	 *
-	 * @param   string  $name      The preset name
-	 * @param   bool    $fallback  Fallback to default (joomla) preset if the specified one could not be loaded?
-	 *
-	 * @return  \stdClass[]
-	 *
-	 * @since   3.8.0
-	 */
-	public static function loadPreset($name, $fallback = true)
-	{
-		$items   = array();
-		$presets = static::getPresets();
-
-		if (isset($presets[$name]) && ($xml = simplexml_load_file($presets[$name]->path, null, LIBXML_NOCDATA)) && $xml instanceof \SimpleXMLElement)
-		{
-			static::loadXml($xml, $items);
-		}
-		elseif ($fallback && isset($presets['joomla']))
-		{
-			if (($xml = simplexml_load_file($presets['joomla']->path, null, LIBXML_NOCDATA)) && $xml instanceof \SimpleXMLElement)
-			{
-				static::loadXml($xml, $items);
-			}
-		}
-
-		return $items;
-	}
-
-	/**
-	 * Method to resolve the menu item alias type menu item
-	 *
-	 * @param   \stdClass  &$item  The alias object
-	 *
-	 * @return  void
-	 *
-	 * @since   3.8.0
-	 */
-	public static function resolveAlias(&$item)
-	{
-		$obj = $item;
-
-		while ($obj->type == 'alias')
-		{
-			$params  = new Registry($obj->params);
-			$aliasTo = $params->get('aliasoptions');
-
-			$db = Factory::getDbo();
-			$query = $db->getQuery(true);
-			$query->select('a.id, a.link, a.type, e.element')
-				->from('#__menu a')
-				->where('a.id = ' . (int) $aliasTo)
-				->join('left', '#__extensions e ON e.id = a.component_id = e.id');
-
-			try
-			{
-				$obj = $db->setQuery($query)->loadObject();
-
-				if (!$obj)
-				{
-					$item->link = '';
-
-					return;
-				}
-			}
-			catch (\Exception $e)
-			{
-				$item->link = '';
-
-				return;
-			}
-		}
-
-		$item->id      = $obj->id;
-		$item->link    = $obj->link;
-		$item->type    = $obj->type;
-		$item->element = $obj->element;
-	}
-
-	/**
-	 * Parse the flat list of menu items and prepare the hierarchy of them using parent-child relationship.
-	 *
-	 * @param   \stdClass[]  $menuItems  List of menu items loaded from database
-	 *
-	 * @return  \stdClass[]
-	 *
-	 * @since   3.8.0
-	 */
-	public static function createLevels($menuItems)
-	{
-		$result    = array();
-		$result[1] = array();
-
-		foreach ($menuItems as $i => &$item)
-		{
-			// Resolve the alias item to get the original item
-			if ($item->type == 'alias')
-			{
-				static::resolveAlias($item);
-			}
-
-			if ($item->link = in_array($item->type, array('separator', 'heading', 'container')) ? '#' : trim($item->link))
-			{
-				$item->submenu    = array();
-				$item->class      = $item->img ?? '';
-				$item->scope      = $item->scope ?? null;
-				$item->browserNav = $item->browserNav ? '_blank' : '';
-
-				$result[$item->parent_id][$item->id] = $item;
-			}
-		}
-
-		// Move each of the items under respective parent menu items.
-		if (count($result[1]))
-		{
-			foreach ($result as $parentId => &$mItems)
-			{
-				foreach ($mItems as &$mItem)
-				{
-					if (isset($result[$mItem->id]))
-					{
-						$mItem->submenu = &$result[$mItem->id];
-					}
-				}
-			}
-		}
-
-		// Return only top level items, subtree follows
-		return $result[1];
-	}
-
-	/**
-	 * Load a menu tree from an XML file
-	 *
-	 * @param   \SimpleXMLElement[]  $elements  The xml menuitem nodes
-	 * @param   \stdClass[]          &$items    The menu hierarchy list to be populated
-	 * @param   string[]             $replace   The substring replacements for iterator type items
-	 *
-	 * @return  void
-	 *
-	 * @since  3.8.0
-	 */
-	protected static function loadXml($elements, &$items, $replace = array())
-	{
-		foreach ($elements as $element)
-		{
-			if ($element->getName() != 'menuitem')
-			{
-				continue;
-			}
-
-			$select = (string) $element['sql_select'];
-			$from   = (string) $element['sql_from'];
-
-			/**
-			 * Following is a repeatable group based on simple database query. This requires sql_* attributes (sql_select and sql_from are required)
-			 * The values can be used like - "{sql:columnName}" in any attribute of repeated elements.
-			 * The repeated elements are place inside this xml node but they will be populated in the same level in the rendered menu
-			 */
-			if ($select && $from)
-			{
-				$hidden = $element['hidden'] == 'true';
-				$where  = (string) $element['sql_where'];
-				$order  = (string) $element['sql_order'];
-				$group  = (string) $element['sql_group'];
-				$lJoin  = (string) $element['sql_leftjoin'];
-				$iJoin  = (string) $element['sql_innerjoin'];
-
-				$db    = Factory::getDbo();
-				$query = $db->getQuery(true);
-				$query->select($select)->from($from);
-
-				if ($where)
-				{
-					$query->where($where);
-				}
-
-				if ($order)
-				{
-					$query->order($order);
-				}
-
-				if ($group)
-				{
-					$query->group($group);
-				}
-
-				if ($lJoin)
-				{
-					$query->leftJoin($lJoin);
-				}
-
-				if ($iJoin)
-				{
-					$query->innerJoin($iJoin);
-				}
-
-				$results = $db->setQuery($query)->loadObjectList();
-
-				// Skip the entire group if no items to iterate over.
-				if ($results)
-				{
-					// Show the repeatable group heading node only if not set as hidden.
-					if (!$hidden)
-					{
-						$items[] = static::parseXmlNode($element, $replace);
-					}
-
-					// Iterate over the matching records, items goes in the same level (not $item->submenu) as this node.
-					foreach ($results as $result)
-					{
-						static::loadXml($element->menuitem, $items, $result);
-					}
-				}
-			}
-			else
-			{
-				$item = static::parseXmlNode($element, $replace);
-
-				// Process the child nodes
-				static::loadXml($element->menuitem, $item->submenu, $replace);
-
-				$items[] = $item;
-			}
-		}
-	}
-
-	/**
-	 * Create a menu item node from an xml element
-	 *
-	 * @param   \SimpleXMLElement  $node     A menuitem element from preset xml
-	 * @param   string[]           $replace  The values to substitute in the title, link and element texts
-	 *
-	 * @return  \stdClass
-	 *
-	 * @since   3.8.0
-	 */
-	protected static function parseXmlNode($node, $replace = array())
-	{
-		$item = new \stdClass;
-
-		$item->id         = null;
-		$item->type       = (string) $node['type'];
-		$item->title      = (string) $node['title'];
-		$item->link       = (string) $node['link'];
-		$item->element    = (string) $node['element'];
-		$item->class      = (string) $node['class'];
-		$item->icon       = (string) $node['icon'];
-		$item->browserNav = (string) $node['target'];
-		$item->access     = (int) $node['access'];
-		$item->params     = new Registry(trim($node->params));
-		$item->scope      = (string) $node['scope'] ?: 'default';
-		$item->submenu    = array();
-
-		if ($item->type == 'separator' && trim($item->title, '- '))
-		{
-			$item->params->set('text_separator', 1);
-		}
-
-		// Translate attributes for iterator values
-		foreach ($replace as $var => $val)
-		{
-			$item->title   = str_replace("{sql:$var}", $val, $item->title);
-			$item->element = str_replace("{sql:$var}", $val, $item->element);
-			$item->link    = str_replace("{sql:$var}", $val, $item->link);
-			$item->class   = str_replace("{sql:$var}", $val, $item->class);
-			$item->icon    = str_replace("{sql:$var}", $val, $item->icon);
-		}
-
-		return $item;
-	}
-}
diff --git a/libraries/src/Menu/MenuItem.php b/libraries/src/Menu/MenuItem.php
index 0aa78b0eb8471..8f37367a1df0d 100644
--- a/libraries/src/Menu/MenuItem.php
+++ b/libraries/src/Menu/MenuItem.php
@@ -10,16 +10,20 @@
 
 defined('JPATH_PLATFORM') or die;
 
+use Joomla\CMS\Menu\AbstractMenu;
+use Joomla\CMS\Tree\NodeInterface;
+use Joomla\CMS\Tree\NodeTrait;
 use Joomla\Registry\Registry;
 
 /**
  * Object representing a menu item
  *
  * @since  3.7.0
- * @note   This class will no longer extend stdClass in Joomla 4
  */
-class MenuItem extends \stdClass
+class MenuItem implements NodeInterface
 {
+	use NodeTrait;
+
 	/**
 	 * Primary key
 	 *
diff --git a/libraries/src/Menu/Node.php b/libraries/src/Menu/Node.php
deleted file mode 100644
index da97db3d536b4..0000000000000
--- a/libraries/src/Menu/Node.php
+++ /dev/null
@@ -1,272 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu;
-
-defined('JPATH_PLATFORM') or die;
-
-use Joomla\Registry\Registry;
-
-/**
- * A Node for MenuTree
- *
- * @see    Tree
- *
- * @since  3.8.0
- */
-class Node
-{
-	/**
-	 * Node Id
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $id = null;
-
-	/**
-	 * CSS Class for node
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $class = null;
-
-	/**
-	 * Whether this node is active
-	 *
-	 * @var  bool
-	 *
-	 * @since   3.8.0
-	 */
-	protected $active = false;
-
-	/**
-	 * Additional custom node params
-	 *
-	 * @var  Registry
-	 *
-	 * @since   3.8.0
-	 */
-	protected $params;
-
-	/**
-	 * Parent node object
-	 *
-	 * @var  Node
-	 *
-	 * @since   3.8.0
-	 */
-	protected $parent = null;
-
-	/**
-	 * Array of Children node objects
-	 *
-	 * @var  Node[]
-	 *
-	 * @since   3.8.0
-	 */
-	protected $children = array();
-
-	/**
-	 * Constructor
-	 *
-	 * @since   3.8.0
-	 */
-	public function __construct()
-	{
-		$this->params = new Registry;
-	}
-
-	/**
-	 * Add child to this node
-	 *
-	 * If the child already has a parent, the link is unset
-	 *
-	 * @param   Node  $child  The child to be added
-	 *
-	 * @return  Node  The new added child
-	 *
-	 * @since   3.8.0
-	 */
-	public function addChild(Node $child)
-	{
-		$hash = spl_object_hash($child);
-
-		if (isset($child->parent))
-		{
-			$child->parent->removeChild($child);
-		}
-
-		$child->parent         = $this;
-		$this->children[$hash] = $child;
-
-		return $child;
-	}
-
-	/**
-	 * Remove a child from this node
-	 *
-	 * If the child exists it is unset
-	 *
-	 * @param   Node  $child  The child to be added
-	 *
-	 * @return  void
-	 *
-	 * @since   3.8.0
-	 */
-	public function removeChild(Node $child)
-	{
-		$hash = spl_object_hash($child);
-
-		if (isset($this->children[$hash]))
-		{
-			$child->parent = null;
-
-			unset($this->children[$hash]);
-		}
-	}
-
-	/**
-	 * Test if this node has a parent
-	 *
-	 * @return  boolean  True if there is a parent
-	 *
-	 * @since   3.8.0
-	 */
-	public function hasParent()
-	{
-		return isset($this->parent);
-	}
-
-	/**
-	 * Get the parent of this node
-	 *
-	 * @return  Node  The Node object's parent or null for no parent
-	 *
-	 * @since   3.8.0
-	 */
-	public function getParent()
-	{
-		return $this->parent;
-	}
-
-	/**
-	 * Test if this node has children
-	 *
-	 * @return  boolean
-	 *
-	 * @since   3.8.0
-	 */
-	public function hasChildren()
-	{
-		return count($this->children) > 0;
-	}
-
-	/**
-	 * Get the children of this node
-	 *
-	 * @return  Node[]  The children
-	 *
-	 * @since   3.8.0
-	 */
-	public function getChildren()
-	{
-		return $this->children;
-	}
-
-	/**
-	 * Find the current node depth in the tree hierarchy
-	 *
-	 * @return  integer  The node level in the hierarchy, where ROOT == 0, First level menu item == 1, and so on.
-	 *
-	 * @since   3.8.0
-	 */
-	public function getLevel()
-	{
-		return $this->hasParent() ? $this->getParent()->getLevel() + 1 : 0;
-	}
-
-	/**
-	 * Check whether the object instance node is the root node
-	 *
-	 * @return  boolean
-	 *
-	 * @since   3.8.0
-	 */
-	public function isRoot()
-	{
-		return !$this->hasParent();
-	}
-
-	/**
-	 * Set the active state on or off
-	 *
-	 * @param   bool  $active  The new active state
-	 *
-	 * @return  void
-	 *
-	 * @since   3.8.0
-	 */
-	public function setActive($active)
-	{
-		$this->active = (bool) $active;
-	}
-
-	/**
-	 * set the params array
-	 *
-	 * @param   Registry  $params  The params attributes
-	 *
-	 * @return  void
-	 *
-	 * @since   3.8.0
-	 */
-	public function setParams(Registry $params)
-	{
-		$this->params = $params;
-	}
-
-	/**
-	 * Get the param value from the node params
-	 *
-	 * @param   string  $key  The param name
-	 *
-	 * @return  mixed
-	 *
-	 * @since   3.8.0
-	 */
-	public function getParam($key)
-	{
-		return $this->params[$key] ?? null;
-	}
-
-	/**
-	 * Get an attribute value
-	 *
-	 * @param   string  $name  The attribute name
-	 *
-	 * @return  mixed
-	 *
-	 * @since   3.8.0
-	 */
-	public function get($name)
-	{
-		switch ($name)
-		{
-			case 'id':
-			case 'class':
-			case 'active':
-			case 'params':
-				return $this->$name;
-		}
-
-		return null;
-	}
-}
diff --git a/libraries/src/Menu/Node/Component.php b/libraries/src/Menu/Node/Component.php
deleted file mode 100644
index eb16726d5523c..0000000000000
--- a/libraries/src/Menu/Node/Component.php
+++ /dev/null
@@ -1,118 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu\Node;
-
-defined('JPATH_PLATFORM') or die;
-
-use Joomla\CMS\Filter\OutputFilter;
-use Joomla\CMS\Menu\Node;
-
-/**
- * A Component type of node for MenuTree
- *
- * @see    Node
- *
- * @since  3.8.0
- */
-class Component extends Node
-{
-	/**
-	 * Node Title
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $title = null;
-
-	/**
-	 * The component name for this node link
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $element = null;
-
-	/**
-	 * Node Link
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $link = null;
-
-	/**
-	 * Link Target
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $target = null;
-
-	/**
-	 * Link title icon
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $icon = null;
-
-	/**
-	 * Constructor for the class.
-	 *
-	 * @param   string  $title    The title of the node
-	 * @param   string  $element  The component name
-	 * @param   string  $link     The node link
-	 * @param   string  $target   The link target
-	 * @param   string  $class    The CSS class for the node
-	 * @param   string  $id       The node id
-	 * @param   string  $icon     The title icon for the node
-	 *
-	 * @since   3.8.0
-	 */
-	public function __construct($title, $element, $link, $target = null, $class = null, $id = null, $icon = null)
-	{
-		$this->title   = $title;
-		$this->element = $element;
-		$this->link    = $link ? OutputFilter::ampReplace($link) : 'index.php?option=' . $element;
-		$this->target  = $target;
-		$this->class   = $class;
-		$this->id      = $id;
-		$this->icon    = $icon;
-
-		parent::__construct();
-	}
-
-	/**
-	 * Get an attribute value
-	 *
-	 * @param   string  $name  The attribute name
-	 *
-	 * @return  mixed
-	 *
-	 * @since   3.8.0
-	 */
-	public function get($name)
-	{
-		switch ($name)
-		{
-			case 'title':
-			case 'element':
-			case 'link':
-			case 'target':
-			case 'icon':
-				return $this->$name;
-		}
-
-		return parent::get($name);
-	}
-}
diff --git a/libraries/src/Menu/Node/Container.php b/libraries/src/Menu/Node/Container.php
deleted file mode 100644
index 506fa504b943d..0000000000000
--- a/libraries/src/Menu/Node/Container.php
+++ /dev/null
@@ -1,21 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu\Node;
-
-defined('JPATH_PLATFORM') or die;
-
-/**
- * A Container type of node for MenuTree
- *
- * @see    Node
- *
- * @since  3.8.0
- */
-class Container extends Heading
-{
-}
diff --git a/libraries/src/Menu/Node/Heading.php b/libraries/src/Menu/Node/Heading.php
deleted file mode 100644
index 2010c48c79a26..0000000000000
--- a/libraries/src/Menu/Node/Heading.php
+++ /dev/null
@@ -1,91 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu\Node;
-
-defined('JPATH_PLATFORM') or die;
-
-use Joomla\CMS\Menu\Node;
-
-/**
- * A Heading type of node for MenuTree
- *
- * @see    Node
- *
- * @since  3.8.0
- */
-class Heading extends Node
-{
-	/**
-	 * Node Title
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $title = null;
-
-	/**
-	 * Node Link
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $link = '#';
-
-	/**
-	 * Link title icon
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $icon = null;
-
-	/**
-	 * Constructor for the class.
-	 *
-	 * @param   string  $title  The title of the node
-	 * @param   string  $class  The CSS class for the node
-	 * @param   string  $id     The node id
-	 * @param   string  $icon   The title icon for the node
-	 *
-	 * @since   3.8.0
-	 */
-	public function __construct($title, $class = null, $id = null, $icon = null)
-	{
-		$this->title = $title;
-		$this->class = $class;
-		$this->id    = $id;
-		$this->icon  = $icon;
-
-		parent::__construct();
-	}
-
-	/**
-	 * Get an attribute value
-	 *
-	 * @param   string  $name  The attribute name
-	 *
-	 * @return  mixed
-	 *
-	 * @since   3.8.0
-	 */
-	public function get($name)
-	{
-		switch ($name)
-		{
-			case 'title':
-			case 'link':
-			case 'icon':
-				return $this->$name;
-		}
-
-		return parent::get($name);
-	}
-}
diff --git a/libraries/src/Menu/Node/Separator.php b/libraries/src/Menu/Node/Separator.php
deleted file mode 100644
index c5eb1f445c9cd..0000000000000
--- a/libraries/src/Menu/Node/Separator.php
+++ /dev/null
@@ -1,65 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu\Node;
-
-defined('JPATH_PLATFORM') or die;
-
-use Joomla\CMS\Menu\Node;
-
-/**
- * A Separator type of node for MenuTree
- *
- * @see    Node
- *
- * @since  3.8.0
- */
-class Separator extends Node
-{
-	/**
-	 * Node Title
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $title = null;
-
-	/**
-	 * Constructor for the class.
-	 *
-	 * @param   string  $title  The title of the node
-	 *
-	 * @since   3.8.0
-	 */
-	public function __construct($title = null)
-	{
-		$this->title = trim($title, '- ') ? $title : null;
-
-		parent::__construct();
-	}
-
-	/**
-	 * Get an attribute value
-	 *
-	 * @param   string  $name  The attribute name
-	 *
-	 * @return  mixed
-	 *
-	 * @since   3.8.0
-	 */
-	public function get($name)
-	{
-		switch ($name)
-		{
-			case 'title':
-				return $this->$name;
-		}
-
-		return parent::get($name);
-	}
-}
diff --git a/libraries/src/Menu/Node/Url.php b/libraries/src/Menu/Node/Url.php
deleted file mode 100644
index 6d043520cffca..0000000000000
--- a/libraries/src/Menu/Node/Url.php
+++ /dev/null
@@ -1,106 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu\Node;
-
-defined('JPATH_PLATFORM') or die;
-
-use Joomla\CMS\Filter\OutputFilter;
-use Joomla\CMS\Menu\Node;
-
-/**
- * An external Url type of node for MenuTree
- *
- * @see    Node
- *
- * @since  3.8.0
- */
-class Url extends Node
-{
-	/**
-	 * Node Title
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $title = null;
-
-	/**
-	 * Node Link
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $link = null;
-
-	/**
-	 * Link Target
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $target = null;
-
-	/**
-	 * Link title icon
-	 *
-	 * @var  string
-	 *
-	 * @since   3.8.0
-	 */
-	protected $icon = null;
-
-	/**
-	 * Constructor for the class.
-	 *
-	 * @param   string  $title   The title of the node
-	 * @param   string  $link    The node link
-	 * @param   string  $target  The link target
-	 * @param   string  $class   The CSS class for the node
-	 * @param   string  $id      The node id
-	 * @param   string  $icon    The title icon for the node
-	 *
-	 * @since   3.8.0
-	 */
-	public function __construct($title, $link, $target = null, $class = null, $id = null, $icon = null)
-	{
-		$this->title  = $title;
-		$this->link   =	OutputFilter::ampReplace($link);
-		$this->target = $target;
-		$this->class  = $class;
-		$this->id     = $id;
-		$this->icon   = $icon;
-
-		parent::__construct();
-	}
-
-	/**
-	 * Get an attribute value
-	 *
-	 * @param   string  $name  The attribute name
-	 *
-	 * @return  mixed
-	 *
-	 * @since   3.8.0
-	 */
-	public function get($name)
-	{
-		switch ($name)
-		{
-			case 'title':
-			case 'link':
-			case 'target':
-			case 'icon':
-				return $this->$name;
-		}
-
-		return parent::get($name);
-	}
-}
diff --git a/libraries/src/Menu/SiteMenu.php b/libraries/src/Menu/SiteMenu.php
index dc1f4d009702f..4eeb4af09b429 100644
--- a/libraries/src/Menu/SiteMenu.php
+++ b/libraries/src/Menu/SiteMenu.php
@@ -129,6 +129,7 @@ public function load()
 
 			if (isset($this->getMenu()[$item->parent_id]))
 			{
+				$item->setParent($this->getMenu()[$item->parent_id]);
 				$parent_tree  = $this->getMenu()[$item->parent_id]->tree;
 			}
 
diff --git a/libraries/src/Menu/Tree.php b/libraries/src/Menu/Tree.php
deleted file mode 100644
index 1a46531b834a2..0000000000000
--- a/libraries/src/Menu/Tree.php
+++ /dev/null
@@ -1,241 +0,0 @@
-<?php
-/**
- * Joomla! Content Management System
- *
- * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
- * @license    GNU General Public License version 2 or later; see LICENSE.txt
- */
-namespace Joomla\CMS\Menu;
-
-defined('JPATH_PLATFORM') or die;
-
-/**
- * Menu Tree class to represent a menu tree hierarchy
- *
- * @since  3.8.0
- */
-class Tree
-{
-	/**
-	 * The root menu node
-	 *
-	 * @var  Node
-	 *
-	 * @since   3.8.0
-	 */
-	protected $root = null;
-
-	/**
-	 * The current working menu node
-	 *
-	 * @var  Node
-	 *
-	 * @since   3.8.0
-	 */
-	protected $current = null;
-
-	/**
-	 * The CSS style array
-	 *
-	 * @var  string[]
-	 *
-	 * @since   3.8.0
-	 */
-	protected $css = array();
-
-	/**
-	 * Counter
-	 *
-	 * @var  int
-	 */
-	protected static $counter = 0;
-
-	/**
-	 * Constructor
-	 *
-	 * @since   3.8.0
-	 */
-	public function __construct()
-	{
-		$this->root    = new Node;
-		$this->current = $this->root;
-	}
-
-	/**
-	 * Get the root node
-	 *
-	 * @return  Node
-	 *
-	 * @since   3.8.0
-	 */
-	public function getRoot()
-	{
-		return $this->root;
-	}
-
-	/**
-	 * Get the current node
-	 *
-	 * @return  Node
-	 *
-	 * @since   3.8.0
-	 */
-	public function getCurrent()
-	{
-		return $this->current;
-	}
-
-	/**
-	 * Get the current node
-	 *
-	 * @param   Node  $node  The node to be set as current
-	 *
-	 * @return  void
-	 *
-	 * @since   3.8.0
-	 */
-	public function setCurrent($node)
-	{
-		if ($node)
-		{
-			$this->current = $node;
-		}
-	}
-
-	/**
-	 * Method to get the parent and set it as active optionally
-	 *
-	 * @param   bool  $setCurrent  Set that parent as the current node for further working
-	 *
-	 * @return  Node
-	 *
-	 * @since   3.8.0
-	 */
-	public function getParent($setCurrent = true)
-	{
-		$parent = $this->current->getParent();
-
-		if ($setCurrent)
-		{
-			$this->setCurrent($parent);
-		}
-
-		return $parent;
-	}
-
-	/**
-	 * Method to reset the working pointer to the root node and optionally clear all menu nodes
-	 *
-	 * @param   bool  $clear  Whether to clear the existing menu items or just reset the pointer to root element
-	 *
-	 * @return  Node  The root node
-	 *
-	 * @since   3.8.0
-	 */
-	public function reset($clear = false)
-	{
-		if ($clear)
-		{
-			$this->root = new Node;
-			$this->css  = array();
-		}
-
-		$this->current = $this->root;
-
-		return  $this->current;
-	}
-
-	/**
-	 * Method to add a child
-	 *
-	 * @param   Node  $node        The node to process
-	 * @param   bool  $setCurrent  Set this new child as the current node for further working
-	 *
-	 * @return  Node  The newly added node
-	 *
-	 * @since   3.8.0
-	 */
-	public function addChild(Node $node, $setCurrent = false)
-	{
-		$this->current->addChild($node);
-
-		if ($setCurrent)
-		{
-			$this->setCurrent($node);
-		}
-
-		return $node;
-	}
-
-	/**
-	 * Method to get the CSS class name for an icon identifier or create one if
-	 * a custom image path is passed as the identifier
-	 *
-	 * @return  string	CSS class name
-	 *
-	 * @since   3.8.0
-	 */
-	public function getIconClass()
-	{
-		static $classes = array();
-
-		$identifier = $this->current->get('class');
-		$html       = '';
-
-		// Top level is special
-		if (trim($identifier) == '' || !$this->current->hasParent())
-		{
-			return null;
-		}
-
-		if (!isset($classes[$identifier]))
-		{
-			// We were passed a class name
-			if (substr($identifier, 0, 6) == 'class:')
-			{
-				$class = substr($identifier, 6);
-			}
-			// We were passed background icon url. Build the CSS class for the icon
-			else
-			{
-				if ($identifier == null)
-				{
-					return null;
-				}
-
-				$class = preg_replace('#\.[^.]*$#', '', basename($identifier));
-				$class = preg_replace('#\.\.[^A-Za-z0-9\.\_\- ]#', '', $class);
-			}
-
-			$html = 'fa-fw fa fa-' . $class;
-		}
-
-		return $html;
-	}
-
-	/**
-	 * Get the CSS declarations for this tree
-	 *
-	 * @return  string[]
-	 *
-	 * @since   3.8.0
-	 */
-	public function getCss()
-	{
-		return $this->css;
-	}
-
-	/**
-	 * Create unique identifier
-	 *
-	 * @return  string
-	 *
-	 * @since   4.0.0
-	 */
-	public function getCounter()
-	{
-		self::$counter++;
-
-		return self::$counter;
-	}
-}
diff --git a/libraries/src/Router/SiteRouter.php b/libraries/src/Router/SiteRouter.php
index 3176830335f47..511e95d03a524 100644
--- a/libraries/src/Router/SiteRouter.php
+++ b/libraries/src/Router/SiteRouter.php
@@ -225,55 +225,46 @@ public function parseSefRoute(&$router, &$uri)
 		else
 		{
 			// Get menu items.
-			$items = $this->menu->getMenu();
+			$items    = $this->menu->getItems('parent_id', 1);
+			$lang_tag = $this->app->getLanguage()->getTag();
+			$found   = null;
 
-			$found           = false;
-			$route_lowercase = StringHelper::strtolower($route);
-			$lang_tag        = $this->app->getLanguage()->getTag();
-
-			// Iterate through all items and check route matches.
-			foreach ($items as $item)
+			foreach ($segments as $segment)
 			{
-				if ($item->route && StringHelper::strpos($route_lowercase . '/', $item->route . '/') === 0 && $item->type !== 'menulink')
+				$matched = false;
+
+				foreach ($items as $item)
 				{
-					// Usual method for non-multilingual site.
-					if (!$this->app->getLanguageFilter())
-					{
-						// Exact route match. We can break iteration because exact item was found.
-						if ($item->route === $route_lowercase)
-						{
-							$found = $item;
-							break;
-						}
-
-						// Partial route match. Item with highest level takes priority.
-						if (!$found || $found->level < $item->level)
-						{
-							$found = $item;
-						}
-					}
-					// Multilingual site.
-					elseif ($item->language === '*' || $item->language === $lang_tag)
+					if ($item->alias == $segment
+						&& (!$this->app->getLanguageFilter() 
+						|| ($item->language === '*' 
+						|| $item->language === $lang_tag)))
 					{
-						// Exact route match.
-						if ($item->route === $route_lowercase)
-						{
-							$found = $item;
-
-							// Break iteration only if language is matched.
-							if ($item->language === $lang_tag)
-							{
-								break;
-							}
-						}
-
-						// Partial route match. Item with highest level or same language takes priority.
-						if (!$found || $found->level < $item->level || $item->language === $lang_tag)
-						{
-							$found = $item;
-						}
+						$found = $item;
+						$matched = true;
+						$items = $item->getChildren();
+						break;
 					}
 				}
+
+				if (!$matched)
+				{
+					break;
+				}
+			}
+
+			// Menu links are not valid URLs. Find the first parent that isn't a menulink
+			if ($found && $found->type == 'menulink')
+			{
+				while ($found->hasParent() && $found->type == 'menulink')
+				{
+					$found = $found->getParent();
+				}
+
+				if ($found->type == 'menulink')
+				{
+					$found = null;
+				}
 			}
 
 			if (!$found)
diff --git a/libraries/src/Tree/ImmutableNodeInterface.php b/libraries/src/Tree/ImmutableNodeInterface.php
index 4a2c296a89113..802b25cb3ed54 100644
--- a/libraries/src/Tree/ImmutableNodeInterface.php
+++ b/libraries/src/Tree/ImmutableNodeInterface.php
@@ -40,7 +40,7 @@ public function getParent();
 	/**
 	 * Get the root of the tree
 	 * 
-	 * @return  NodeInterface
+	 * @return  ImmutableNodeInterface
 	 * 
 	 * @since   __DEPLOY_VERSION__
 	 */
diff --git a/libraries/src/Tree/ImmutableNodeTrait.php b/libraries/src/Tree/ImmutableNodeTrait.php
new file mode 100644
index 0000000000000..7d153607e4a41
--- /dev/null
+++ b/libraries/src/Tree/ImmutableNodeTrait.php
@@ -0,0 +1,159 @@
+<?php
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\Tree;
+
+defined('JPATH_PLATFORM') or die;
+
+/**
+ * Defines the trait for an Immutable Node Class.
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+trait ImmutableNodeTrait
+{
+	/**
+	 * Parent node object
+	 *
+	 * @var    NodeInterface
+	 * @since  1.6
+	 */
+	protected $_parent = null;
+
+	/**
+	 * Array of Children
+	 *
+	 * @var    NodeInterface[]
+	 * @since  1.6
+	 */
+	protected $_children = array();
+
+	/**
+	 * Node left of this one
+	 *
+	 * @var    NodeInterface
+	 * @since  1.6
+	 */
+	protected $_leftSibling = null;
+
+	/**
+	 * Node right of this one
+	 *
+	 * @var    NodeInterface
+	 * @since  1.6
+	 */
+	protected $_rightSibling = null;
+
+	/**
+	 * Get the children of this node
+	 *
+	 * @param   boolean  $recursive  False by default
+	 *
+	 * @return  NodeInterface[]  The children
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function &getChildren($recursive = false)
+	{
+		if ($recursive)
+		{
+			$items = array();
+
+			foreach ($this->_children as $child)
+			{
+				$items[] = $child;
+				$items = array_merge($items, $child->getChildren(true));
+			}
+
+			return $items;
+		}
+
+		return $this->_children;
+	}
+
+	/**
+	 * Get the parent of this node
+	 *
+	 * @return  NodeInterface|null
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getParent()
+	{
+		return $this->_parent;
+	}
+
+	/**
+	 * Get the root of the tree
+	 * 
+	 * @return  ImmutableNodeInterface
+	 * 
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getRoot()
+	{
+		$root = $this->getParent();
+
+		if (!$root)
+		{
+			return $this;
+		}
+
+		while ($root->hasParent())
+		{
+			$root = $root->getParent();
+		}
+
+		return $root;
+	}
+
+	/**
+	 * Test if this node has children
+	 *
+	 * @return  boolean  True if there is a child
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function hasChildren()
+	{
+		return (bool) count($this->_children);
+	}
+
+	/**
+	 * Test if this node has a parent
+	 *
+	 * @return  boolean  True if there is a parent
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function hasParent()
+	{
+		return $this->getParent() != null;
+	}
+
+	/**
+	 * Returns the right or left sibling of a node
+	 *
+	 * @param   boolean  $right  If set to false, returns the left sibling
+	 *
+	 * @return  NodeInterface|null  NodeInterface object of the sibling.
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function getSibling($right = true)
+	{
+		if ($right)
+		{
+			return $this->_rightSibling;
+		}
+		else
+		{
+			return $this->_leftSibling;
+		}
+	}
+}
diff --git a/libraries/src/Tree/NodeInterface.php b/libraries/src/Tree/NodeInterface.php
index aa29b51385eb9..21e9dd3d64e6e 100644
--- a/libraries/src/Tree/NodeInterface.php
+++ b/libraries/src/Tree/NodeInterface.php
@@ -28,7 +28,7 @@ interface NodeInterface extends ImmutableNodeInterface
 	 *
 	 * @since   __DEPLOY_VERSION__
 	 */
-	public function setParent($parent);
+	public function setParent(NodeInterface $parent);
 
 	/**
 	 * Add child to this node
@@ -41,18 +41,18 @@ public function setParent($parent);
 	 *
 	 * @since   __DEPLOY_VERSION__
 	 */
-	public function addChild($child);
+	public function addChild(NodeInterface $child);
 
 	/**
 	 * Remove a specific child
 	 *
-	 * @param   integer  $id  ID of a node
+	 * @param   NodeInterface  $child  Child to remove
 	 *
 	 * @return  void
 	 *
 	 * @since   __DEPLOY_VERSION__
 	 */
-	public function removeChild($id);
+	public function removeChild(NodeInterface $child);
 
 	/**
 	 * Function to set the left or right sibling of a node
@@ -64,5 +64,5 @@ public function removeChild($id);
 	 *
 	 * @since   __DEPLOY_VERSION__
 	 */
-	public function setSibling($sibling, $right = true);
+	public function setSibling(NodeInterface $sibling, $right = true);
 }
diff --git a/libraries/src/Tree/NodeTrait.php b/libraries/src/Tree/NodeTrait.php
new file mode 100644
index 0000000000000..3dca9506f1fb7
--- /dev/null
+++ b/libraries/src/Tree/NodeTrait.php
@@ -0,0 +1,108 @@
+<?php
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\Tree;
+
+defined('JPATH_PLATFORM') or die;
+
+use Joomla\CMS\Tree\ImmutableNodeTrait;
+use Joomla\CMS\Tree\NodeInterface;
+
+/**
+ * Defines the trait for a Node Interface Trait Class.
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+trait NodeTrait
+{
+	use ImmutableNodeTrait;
+
+	/**
+	 * Set the parent of this node
+	 *
+	 * If the node already has a parent, the link is unset
+	 *
+	 * @param   NodeInterface|null  $parent  NodeInterface for the parent to be set or null
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function setParent(NodeInterface $parent)
+	{
+		if (!is_null($this->_parent))
+		{
+			$key = array_search($this, $this->_parent->_children);
+			unset($this->_parent->_children[$key]);
+		}
+
+		$this->_parent = $parent;
+
+		$this->_parent->_children[] = &$this;
+
+		if (count($this->_parent->_children) > 1)
+		{
+			end($this->_parent->_children);
+			$this->_leftSibling = prev($this->_parent->_children);
+			$this->_leftSibling->_rightSibling = $this;
+		}
+	}
+
+	/**
+	 * Add child to this node
+	 *
+	 * If the child already has a parent, the link is unset
+	 *
+	 * @param   NodeInterface  $child  The child to be added.
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function addChild(NodeInterface $child)
+	{
+		$child->setParent($this);
+	}
+
+	/**
+	 * Remove a specific child
+	 *
+	 * @param   NodeInterface  $child  Child to remove
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function removeChild(NodeInterface $child)
+	{
+		$key = array_search($child, $this->_children);
+		unset($this->_children[$key]);
+	}
+
+	/**
+	 * Function to set the left or right sibling of a node
+	 *
+	 * @param   NodeInterface  $sibling  NodeInterface object for the sibling
+	 * @param   boolean        $right    If set to false, the sibling is the left one
+	 *
+	 * @return  void
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function setSibling(NodeInterface $sibling, $right = true)
+	{
+		if ($right)
+		{
+			$this->_rightSibling = $sibling;
+		}
+		else
+		{
+			$this->_leftSibling = $sibling;
+		}
+	}
+}