diff --git a/wp-includes/class-wp-customize-section.php b/wp-includes/class-wp-customize-section.php
new file mode 100644
index 0000000000..ca8f1da625
--- /dev/null
+++ b/wp-includes/class-wp-customize-section.php
@@ -0,0 +1,83 @@
+<?php
+/**
+ * Customize Section Class
+ *
+ * @package WordPress
+ * @subpackage Customize
+ * @since 3.4.0
+ */
+
+class WP_Customize_Section {
+	public $id;
+	public $priority       = 10;
+	public $capability     = 'edit_theme_options';
+	public $theme_supports = '';
+	public $title          = '';
+	public $description    = '';
+	public $settings;
+
+	/**
+	 * Constructor.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the section.
+	 * @param array $args Section arguments.
+	 */
+	function __construct( $id, $args = array() ) {
+		$this->id = $id;
+
+		$keys = array_keys( get_class_vars( __CLASS__ ) );
+		foreach ( $keys as $key ) {
+			if ( isset( $args[ $key ] ) )
+				$this->$key = $args[ $key ];
+		}
+
+		$this->settings = array(); // Users cannot customize the $settings array.
+
+		return $this;
+	}
+
+	/**
+	 * Check if the theme supports the section and check user capabilities.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return bool False if theme doesn't support the section or user doesn't have the capability.
+	 */
+	function check_capabilities() {
+		if ( ! $this->capability || ! current_user_can( $this->capability ) )
+			return false;
+
+		if ( $this->theme_supports && ! current_theme_supports( $this->theme_supports ) )
+			return false;
+
+		return true;
+	}
+
+	/**
+	 * Render the section.
+	 *
+	 * @since 3.4.0
+	 */
+	function render() {
+		if ( ! $this->check_capabilities() )
+			return;
+		?>
+		<li id="customize-section-<?php echo esc_attr( $this->id ); ?>" class="control-section customize-section">
+			<h3 class="customize-theme-title"><?php echo esc_html( $this->title ); ?></h3>
+			<ul>
+				<?php if ( $this->description ) : ?>
+					<li><p class="howto"><?php echo $this->description; ?></p></li>
+				<?php endif; ?>
+
+				<?php foreach ( $this->settings as $setting ) : ?>
+				<li>
+					<?php $setting->_render(); ?>
+				</li>
+				<?php endforeach; ?>
+			</ul>
+		</li>
+		<?php
+	}
+}
diff --git a/wp-includes/class-wp-customize-setting.php b/wp-includes/class-wp-customize-setting.php
new file mode 100644
index 0000000000..2f68800123
--- /dev/null
+++ b/wp-includes/class-wp-customize-setting.php
@@ -0,0 +1,489 @@
+<?php
+/**
+ * Customize Setting Class
+ *
+ * @package WordPress
+ * @subpackage Customize
+ * @since 3.4.0
+ */
+ 
+class WP_Customize_Setting {
+	public $id;
+	public $priority          = 10;
+	public $section           = '';
+	public $label             = '';
+	public $control           = 'text';
+	public $type              = 'theme_mod';
+	public $choices           = array();
+	public $capability        = 'edit_theme_options';
+	public $theme_supports    = '';
+	public $default           = '';
+	public $sanitize_callback = '';
+
+	protected $id_data = array();
+	private $_post_value; // Cached, sanitized $_POST value.
+
+	// Prefix for $_POST values to prevent naming conflicts.
+	const name_prefix = 'customize_';
+
+	/**
+	 * Constructor.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the setting. Can be a
+	 *                   theme mod or option name.
+	 * @param array $args Setting arguments.
+	 */
+	function __construct( $id, $args = array() ) {
+		$keys = array_keys( get_class_vars( __CLASS__ ) );
+		foreach ( $keys as $key ) {
+			if ( isset( $args[ $key ] ) )
+				$this->$key = $args[ $key ];
+		}
+
+		$this->id = $id;
+
+		// Parse the ID for array keys.
+		$this->id_data[ 'keys' ] = preg_split( '/\[/', str_replace( ']', '', $this->id ) );
+		$this->id_data[ 'base' ] = array_shift( $this->id_data[ 'keys' ] );
+
+		// Rebuild the ID.
+		$this->id = $this->id_data[ 'base' ];
+		if ( ! empty( $this->id_data[ 'keys' ] ) )
+			$this->id .= '[' . implode( '][', $this->id_data[ 'keys' ] ) . ']';
+
+		if ( $this->sanitize_callback != '' )
+			add_filter( "customize_sanitize_{$this->id}", $this->sanitize_callback );
+
+		return $this;
+	}
+
+	/**
+	 * Enqueue setting related scripts/styles.
+	 *
+	 * @since 3.4.0
+	 */
+	public function enqueue() {
+		switch( $this->control ) {
+			case 'color':
+				wp_enqueue_script( 'farbtastic' );
+				wp_enqueue_style( 'farbtastic' );
+				break;
+		}
+	}
+
+	/**
+	 * Handle previewing the setting.
+	 *
+	 * @since 3.4.0
+	 */
+	public function preview() {
+		switch( $this->type ) {
+			case 'theme_mod' :
+				add_filter( 'theme_mod_' . $this->id_data[ 'base' ], array( $this, '_preview_filter' ) );
+				break;
+			case 'option' :
+				if ( empty( $this->id_data[ 'keys' ] ) )
+					add_filter( 'pre_option_' . $this->id_data[ 'base' ], array( $this, '_preview_filter' ) );
+				else
+					add_filter( 'option_' . $this->id_data[ 'base' ], array( $this, '_preview_filter' ) );
+				break;
+			default :
+				do_action( 'customize_preview_' . $this->id );
+		}
+	}
+
+	/**
+	 * Callback function to filter the theme mods and options.
+	 *
+	 * @since 3.4.0
+	 * 
+	 * @param mixed Old value.
+	 * @return mixed New or old value.
+	 */
+	public function _preview_filter( $original ) {
+		return $this->multidimensional_replace( $original, $this->id_data[ 'keys' ], $this->post_value() );
+	}
+
+	/**
+	 * Set the value of the parameter for a specific theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return bool False if cap check fails or value isn't set.
+	 */
+	public final function save() {
+		$value = $this->post_value();
+
+		if ( ! $this->check_capabilities() || ! isset( $value ) )
+			return false;
+
+		do_action( 'customize_save_' . $this->id_data[ 'base' ] );
+
+		$this->update( $value );
+	}
+
+	/**
+	 * Fetches, validates, and sanitizes the $_POST value.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $default mixed A default value which is used as a fallback. Default is null.
+	 * @return mixed Either the default value on failure or sanitized value.
+	 */
+	public final function post_value( $default = null ) {
+		if ( isset( $this->_post_value ) )
+			return $this->_post_value;
+
+		$base = self::name_prefix . $this->id_data[ 'base' ];
+
+		if ( ! isset( $_POST[ $base ] ) )
+			return $default;
+
+		$result = $this->multidimensional_get( $_POST[ $base ], $this->id_data[ 'keys' ] );
+		if ( ! isset( $result ) )
+			return $default;
+
+		$result = $this->sanitize( $result );
+		if ( isset( $result ) )
+			return $this->_post_value = $result;
+		else
+			return $default;
+	}
+
+	/**
+	 * Sanitize an input.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $value mixed The value to sanitize.
+	 * @return mixed Null if an input isn't valid, otherwise the sanitized value.
+	 */
+	public function sanitize( $value ) {
+		return apply_filters( "customize_sanitize_{$this->id}", $value );
+	}
+
+	/**
+	 * Set the value of the parameter for a specific theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $value mixed The value to update.
+	 * @return mixed The result of saving the value.
+	 */
+	protected function update( $value ) {
+		switch( $this->type ) {
+			case 'theme_mod' :
+				return $this->_update_theme_mod( $value );
+				break;
+			case 'option' :
+				return $this->_update_option( $value );
+				break;
+			default :
+				return do_action( 'customize_update_' . $this->type, $value );
+		}
+	}
+
+	/**
+	 * Update the theme mod from the value of the parameter.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $value mixed The value to update.
+	 * @return mixed The result of saving the value.
+	 */
+	protected function _update_theme_mod( $value ) {
+		// Handle non-array theme mod.
+		if ( empty( $this->id_data[ 'keys' ] ) )
+			return set_theme_mod( $this->id_data[ 'base' ], $value );
+
+		// Handle array-based theme mod.
+		$mods = get_theme_mod( $this->id_data[ 'base' ] );
+		$mods = $this->multidimensional_replace( $mods, $this->id_data[ 'keys' ], $value );
+		if ( isset( $mods ) )
+			return set_theme_mod( $this->id_data[ 'base' ], $mods );
+	}
+
+	/**
+	 * Update the theme mod from the value of the parameter.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $value mixed The value to update.
+	 * @return mixed The result of saving the value.
+	 */
+	protected function _update_option( $value ) {
+		// Handle non-array option.
+		if ( empty( $this->id_data[ 'keys' ] ) )
+			return update_option( $this->id_data[ 'base' ], $value );
+
+		// Handle array-based options.
+		$options = get_option( $this->id_data[ 'base' ] );
+		$options = $this->multidimensional_replace( $options, $this->id_data[ 'keys' ], $value );
+		if ( isset( $options ) )
+			return update_option( $this->id_data[ 'base' ], $options );
+	}
+
+	/**
+	 * Fetch the value of the parameter for a specific theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return mixed The requested value.
+	 */
+	public function value() {
+		switch( $this->type ) {
+			case 'theme_mod' :
+				$function = 'get_theme_mod';
+				break;
+			case 'option' :
+				$function = 'get_option';
+				break;
+			default :
+				return apply_filters( 'customize_value_' . $this->id_data[ 'base' ], $this->default );
+		}
+
+		// Handle non-array value
+		if ( empty( $this->id_data[ 'keys' ] ) )
+			return $function( $this->id_data[ 'base' ], $this->default );
+
+		// Handle array-based value
+		$values = $function( $this->id_data[ 'base' ] );
+		return $this->multidimensional_get( $values, $this->id_data[ 'keys' ], $this->default );
+	}
+
+	/**
+	 * Check if the theme supports the setting and check user capabilities.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return bool False if theme doesn't support the setting or user can't change setting, otherwise true.
+	 */
+	public final function check_capabilities() {
+		global $customize;
+
+		if ( ! $this->capability || ! current_user_can( $this->capability ) )
+			return false;
+
+		if ( $this->theme_supports && ! current_theme_supports( $this->theme_supports ) )
+			return false;
+
+		$section = $customize->get_section( $this->section );
+		if ( isset( $section ) && ! $section->check_capabilities() )
+			return false;
+
+		return true;
+	}
+
+	/**
+	 * Render the control.
+	 *
+	 * @since 3.4.0
+	 */
+	public final function _render() {
+		if ( ! $this->check_capabilities() )
+			return;
+
+		do_action( 'customize_render_' . $this->id );
+
+		$this->render();
+	}
+
+	/**
+	 * Render the control.
+	 *
+	 * @since 3.4.0
+	 */
+	protected function render() {
+		$this->_render_type();
+	}
+
+	/**
+	 * Retrieve the name attribute for an input.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return string The name.
+	 */
+	public final function get_name() {
+		return self::name_prefix . esc_attr( $this->id );
+	}
+
+	/**
+	 * Echo the HTML name attribute for an input.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return string The HTML name attribute.
+	 */
+	public final function name() {
+		echo 'name="' . $this->get_name() . '"';
+	}
+
+	/**
+	 * Render the control type.
+	 *
+	 * @todo Improve value and checked attributes.
+	 *
+	 * @since 3.4.0
+	 */
+	public final function _render_type() {
+		switch( $this->control ) {
+			case 'text':
+				?>
+				<label><?php echo esc_html( $this->label ); ?><br/>
+					<input type="text" value="<?php echo esc_attr( $this->value() ); ?>" <?php $this->name(); ?> />
+				</label>
+				<?php
+				break;
+			case 'color':
+				?>
+				<label><?php echo esc_html( $this->label ); ?><br/>
+					<span class="hex-prepend">#</span>
+					<input type="text" class="hex-input" value="<?php echo esc_attr( $this->value() ); ?>" <?php $this->name(); ?> />
+					<a href="#" class="pickcolor hex-color-example"></a>
+				</label>
+				<?php
+				break;
+			case 'checkbox':
+				?>
+				<label>
+					<input type="checkbox" value="<?php echo esc_attr( $this->value() ); ?>" <?php $this->name(); checked( $this->value() ); ?> />
+					<?php echo esc_html( $this->label ); ?>
+				</label>
+				<?php
+				break;
+			case 'radio':
+				if ( empty( $this->choices ) )
+					return;
+
+				echo esc_html( $this->label ) . '<br/>';
+				foreach ( $this->choices as $value => $label ) :
+					?>
+					<label>
+						<input type="radio" value="<?php echo esc_attr( $value ); ?>" <?php $this->name(); checked( $this->value(), $value ); ?> />
+						<?php echo esc_html( $label ); ?><br/>
+					</label>
+					<?php
+				endforeach;
+				break;
+			case 'select':
+				if ( empty( $this->choices ) )
+					return;
+
+				?>
+				<label><?php echo esc_html( $this->label ); ?><br/>
+				<select <?php $this->name(); ?>>
+					<?php
+					foreach ( $this->choices as $value => $label )
+						echo '<option value="' . esc_attr( $value ) . '"' . selected( $this->value(), $value, false ) . '>' . $label . '</option>';
+					?>
+				</select>
+				<?php
+				break;
+			default:
+				do_action( 'customize_render_control-' . $this->control, $this );
+
+		}
+	}
+
+	/**
+	 * Multidimensional helper function.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $root
+	 * @param $keys
+	 * @param bool $create Default is false.
+	 * @return null|array
+	 */
+	final protected function multidimensional( $root, $keys, $create = false ) {
+		if ( $create && empty( $root ) )
+			$root = array();
+
+		if ( ! isset( $root ) || empty( $keys ) )
+			return;
+
+		$last = array_pop( $keys );
+		$node = &$root;
+
+		foreach ( $keys as $key ) {
+			if ( $create && ! isset( $node[ $key ] ) )
+				$node[ $key ] = array();
+
+			if ( ! is_array( $node ) || ! isset( $node[ $key ] ) )
+				return;
+
+			$node = &$node[ $key ];
+		}
+
+		if ( $create && ! isset( $node[ $last ] ) )
+			$node[ $last ] = array();
+
+		if ( ! isset( $node[ $last ] ) )
+			return;
+
+		return array(
+			'root' => &$root,
+			'node' => &$node,
+			'key'  => $last,
+		);
+	}
+
+	/**
+	 * Will attempt to replace a specific value in a multidimensional array.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $root
+	 * @param $keys
+	 * @param mixed $value The value to update.
+	 * @return
+	 */
+	final protected function multidimensional_replace( $root, $keys, $value ) {
+		if ( ! isset( $value ) )
+			return $root;
+		elseif ( empty( $keys ) ) // If there are no keys, we're replacing the root.
+			return $value;
+
+		$result = $this->multidimensional( &$root, $keys, true );
+
+		if ( isset( $result ) )
+			$result['node'][ $result['key'] ] = $value;
+
+		return $root;
+	}
+
+	/**
+	 * Will attempt to fetch a specific value from a multidimensional array.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $root
+	 * @param $keys
+	 * @param $default A default value which is used as a fallback. Default is null.
+	 * @return mixed The requested value or the default value.
+	 */
+	final protected function multidimensional_get( $root, $keys, $default = null ) {
+		if ( empty( $keys ) ) // If there are no keys, test the root.
+			return isset( $root ) ? $root : $default;
+
+		$result = $this->multidimensional( $root, $keys );
+		return isset( $result ) ? $result['node'][ $result['key'] ] : $default;
+	}
+
+	/**
+	 * Will attempt to check if a specific value in a multidimensional array is set.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param $root
+	 * @param $keys
+	 * @return bool True if value is set, false if not.
+	 */
+	final protected function multidimensional_isset( $root, $keys ) {
+		$result = $this->multidimensional_get( $root, $keys );
+		return isset( $result );
+	}
+}
diff --git a/wp-includes/class-wp-customize.php b/wp-includes/class-wp-customize.php
new file mode 100644
index 0000000000..39eb8cce0e
--- /dev/null
+++ b/wp-includes/class-wp-customize.php
@@ -0,0 +1,660 @@
+<?php
+/**
+ * Customize
+ *
+ * @package WordPress
+ * @subpackage Customize
+ * @since 3.4.0
+ */
+
+final class WP_Customize {
+	protected $template;
+	protected $stylesheet;
+	protected $previewing = false;
+
+	protected $settings = array();
+	protected $sections = array();
+
+	/**
+	 * Constructor.
+	 *
+	 * @since 3.4.0
+	 */
+	public function __construct() {
+		require( ABSPATH . WPINC . '/class-wp-customize-setting.php' );
+		require( ABSPATH . WPINC . '/class-wp-customize-section.php' );
+
+		add_action( 'setup_theme',  array( $this, 'setup_theme' ) );
+		add_action( 'admin_init',   array( $this, 'admin_init' ) );
+		add_action( 'init',         array( $this, 'init' ) );
+		add_action( 'admin_footer', array( $this, 'admin_footer' ) );
+
+		add_action( 'customize_previewing',    array( $this, 'customize_previewing' ) );
+		add_action( 'customize_register',      array( $this, 'register_controls' ) );
+		add_action( 'customize_controls_init', array( $this, 'prepare_controls' ) );
+	}
+
+	/**
+	 * Update theme modifications for the current theme.
+	 * Note: Candidate core function.
+	 * http://core.trac.wordpress.org/ticket/20091
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param array $mods Theme modifications.
+	 */
+	public function set_theme_mods( $mods ) {
+		$current = get_theme_mods();
+
+		$mods = wp_parse_args( $mods, $current );
+
+		$theme = get_stylesheet();
+		update_option( "theme_mods_$theme", $mods );
+	}
+
+	/**
+	 * Start preview and customize theme.
+	 * Check if customize query variable exist.
+	 *
+	 * @since 3.4.0
+	 */
+	public function setup_theme() {
+		if ( ! isset( $_REQUEST['customize'] ) || 'on' != $_REQUEST['customize'] )
+			return;
+
+		if ( ! $this->set_stylesheet() || isset( $_REQUEST['save'] ) )
+			return;
+
+		$this->previewing = true;
+		do_action( 'customize_previewing' );
+	}
+
+	/**
+	 * Init filters to filter theme options.
+	 *
+	 * @since 3.4.0
+	 */
+	public function customize_previewing() {
+		global $wp_theme_directories;
+
+		show_admin_bar( false );
+
+		add_filter( 'template', array( $this, 'get_template' ) );
+		add_filter( 'stylesheet', array( $this, 'get_stylesheet' ) );
+		add_filter( 'pre_option_current_theme', array( $this, 'current_theme' ) );
+
+		// @link: http://core.trac.wordpress.org/ticket/20027
+		add_filter( 'pre_option_stylesheet', array( $this, 'get_stylesheet' ) );
+		add_filter( 'pre_option_template', array( $this, 'get_template' ) );
+
+		// Handle custom theme roots.
+		if ( count( $wp_theme_directories ) > 1 ) {
+			add_filter( 'pre_option_stylesheet_root', array( $this, 'get_stylesheet_root' ) );
+			add_filter( 'pre_option_template_root', array( $this, 'get_template_root' ) );
+		}
+	}
+
+	/**
+	 * Register styles/scripts and Init the preview of each setting
+	 *
+	 * @since 3.4.0
+	 */
+	public function init() {
+		do_action( 'customize_register' );
+
+		if ( ! $this->is_preview() )
+			return;
+
+		wp_enqueue_script( 'customize-preview' );
+		add_action( 'wp_footer', array( $this, 'customize_preview_settings' ), 20 );
+
+		foreach ( $this->settings as $setting ) {
+			$setting->preview();
+		}
+	}
+
+	/**
+	 * Print javascript settings.
+	 *
+	 * @since 3.4.0
+	 */
+	public function customize_preview_settings() {
+		$settings = array(
+			// @todo: Perhaps grab the URL via $_POST?
+			'parent' => esc_url( admin_url( 'themes.php' ) ),
+		);
+		?>
+		<script type="text/javascript">
+			(function() {
+				if ( typeof wp === 'undefined' || ! wp.customize )
+					return;
+
+				wp.customize.settings = <?php echo json_encode( $settings ); ?>;
+			})();
+		</script>
+		<?php
+	}
+
+	/**
+	 * Is it a theme preview?
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return bool True if it's a preview, false if not.
+	 */
+	public function is_preview() {
+		return (bool) $this->previewing;
+	}
+
+	/**
+	 * Set the template name of the previewed theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return bool|string Template name.
+	 */
+	public function set_template() {
+		if ( ! empty( $this->template ) )
+			return $this->template;
+
+		$template = preg_replace('|[^a-z0-9_./-]|i', '', $_REQUEST['template'] );
+		if ( validate_file( $template ) )
+			return false;
+
+		return $this->template = $template;
+	}
+
+	/**
+	 * Set the stylesheet name of the previewed theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return bool|string Stylesheet name.
+	 */
+	public function set_stylesheet() {
+		if ( ! empty( $this->stylesheet ) )
+			return $this->stylesheet;
+
+		$this->set_template();
+		if ( empty( $this->template ) )
+			return false;
+
+		if ( empty( $_REQUEST['stylesheet'] ) ) {
+			$stylesheet = $this->template;
+		} else {
+			$stylesheet = preg_replace( '|[^a-z0-9_./-]|i', '', $_REQUEST['stylesheet'] );
+			if ( $stylesheet != $this->template && validate_file( $stylesheet ) )
+				return false;
+		}
+		return $this->stylesheet = $stylesheet;
+
+	}
+
+	/**
+	 * Retrieve the template name of the previewed theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return string Template name.
+	 */
+	public function get_template() {
+		return $this->template;
+	}
+
+	/**
+	 * Retrieve the stylesheet name of the previewed theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return string Stylesheet name.
+	 */
+	public function get_stylesheet() {
+		return $this->stylesheet;
+	}
+
+	/**
+	 * Retrieve the template root of the previewed theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return string Theme root.
+	 */
+	public function get_template_root() {
+		return get_raw_theme_root( $this->template, true );
+	}
+
+	/**
+	 * Retrieve the stylesheet root of the previewed theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return string Theme root.
+	 */
+	public function get_stylesheet_root() {
+		return get_raw_theme_root( $this->stylesheet, true );
+	}
+
+	/**
+	 * Filter the current theme and return the name of the previewed theme.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @return string Theme name.
+	 */
+	public function current_theme( $current_theme ) {
+		$themes = get_themes();
+
+		if ( ! $themes )
+			return $current_theme;
+
+		foreach ( $themes as $theme ) {
+			if ( $theme['Stylesheet'] == $this->stylesheet && $theme['Template'] == $this->template )
+				return $theme['Name'];
+		}
+
+		return $current_theme;
+	}
+
+	/**
+	 * Trigger save action and load customize controls.
+	 *
+	 * @since 3.4.0
+	 */
+	public function admin_init() {
+		if ( isset( $_REQUEST['save'] ) )
+			$this->save();
+
+		wp_enqueue_script( 'customize-loader' );
+		wp_enqueue_style( 'customize-loader' );
+
+		if ( ( defined( 'DOING_AJAX' ) && DOING_AJAX ) )
+			return;
+
+		if ( ! isset( $_GET['customize'] ) || 'on' != $_GET['customize'] )
+			return;
+
+		if ( ! $this->is_preview() )
+			return;
+
+		if ( ! current_user_can( 'edit_theme_options' ) )
+			return;
+
+		include( ABSPATH . WPINC . '/customize-controls.php' );
+
+		die;
+	}
+
+	/**
+	 * Print the customize template.
+	 *
+	 * @since 3.4.0
+	 */
+	public function admin_footer() {
+		?>
+		<div id="customize-container">
+			<input type="hidden" class="admin-url" value="<?php echo esc_url( admin_url( 'admin.php' ) ); ?>" />
+			<div>
+				<a href="#" class="return-to-admin"><?php printf( __( '&larr; Return to %s' ), get_admin_page_title() ); ?></a>
+				<a href="#" class="collapse-sidebar button-secondary" title="<?php esc_attr_e('Collapse Sidebar'); ?>"><span></span></a>
+			</div>
+		</div>
+		<?php
+	}
+
+	/**
+	 * Switch the theme and trigger the save action of each setting.
+	 *
+	 * @since 3.4.0
+	 */
+	public function save() {
+		if ( $this->is_preview() )
+			return;
+
+		check_admin_referer( 'customize_controls' );
+
+		if ( ! $this->set_stylesheet() )
+			return;
+
+		$active_template   = get_template();
+		$active_stylesheet = get_stylesheet();
+
+		// Do we have to switch themes?
+		if ( $this->get_template() != $active_template || $this->get_stylesheet() != $active_stylesheet ) {
+			if ( ! current_user_can( 'switch_themes' ) )
+				return;
+
+			switch_theme( $this->get_template(), $this->get_stylesheet() );
+		}
+
+		do_action( 'customize_save' );
+
+		foreach ( $this->settings as $setting ) {
+			$setting->save();
+		}
+
+		add_action( 'admin_notices', array( $this, '_save_feedback' ) );
+	}
+
+	/**
+	 * Show an admin notice after settings are saved.
+	 *
+	 * @since 3.4.0
+	 */
+	public function _save_feedback() {
+		?>
+		<div class="updated"><p><?php printf( __( 'Settings saved and theme activated. <a href="%s">Visit site</a>.' ), home_url( '/' ) ); ?></p></div>
+		<?php
+	}
+
+	/**
+	 * Add a customize setting.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the setting. Can be a
+	 *                   theme mod or option name.
+	 * @param array $args Setting arguments.
+	 */
+	public function add_setting( $id, $args = array() ) {
+		$setting = new WP_Customize_Setting( $id, $args );
+
+		$this->settings[ $setting->id ] = $setting;
+	}
+
+	/**
+	 * Retrieve a customize setting.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the setting.
+	 * @return object The settings object.
+	 */
+	public function get_setting( $id ) {
+		if ( isset( $this->settings[ $id ] ) )
+			return $this->settings[ $id ];
+	}
+
+	/**
+	 * Remove a customize setting.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the setting.
+	 */
+	public function remove_setting( $id ) {
+		unset( $this->settings[ $id ] );
+	}
+
+	/**
+	 * Add a customize section.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the section.
+	 * @param array $args Section arguments.
+	 */
+	public function add_section( $id, $args = array() ) {
+		$section = new WP_Customize_Section( $id, $args );
+
+		$this->sections[ $section->id ] = $section;
+	}
+
+	/**
+	 * Retrieve a customize section.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the section.
+	 * @return object The section object.
+	 */
+	public function get_section( $id ) {
+		if ( isset( $this->sections[ $id ] ) )
+			return $this->sections[ $id ];
+	}
+
+	/**
+	 * Remove a customize section.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $id An specific ID of the section.
+	 */
+	public function remove_section( $id ) {
+		unset( $this->sections[ $id ] );
+	}
+
+	/**
+	 * Helper function to compare two objects by priority.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param object $a Object A.
+	 * @param object $b Object B.
+	 */
+	protected function _cmp_priority( $a, $b ) {
+		$ap = $a->priority;
+		$bp = $b->priority;
+
+		if ( $ap == $bp )
+			return 0;
+		return ( $ap > $bp ) ? 1 : -1;
+	}
+
+	/**
+	 * Prepare settings and sections. Also enqueue needed scripts/styles.
+	 *
+	 * @since 3.4.0
+	 */
+	public function prepare_controls() {
+		// Reversing makes uasort sort by time added when conflicts occur.
+
+		$this->sections = array_reverse( $this->sections );
+		uasort( $this->sections, array( $this, '_cmp_priority' ) );
+
+		$this->settings = array_reverse( $this->settings );
+		foreach ( $this->settings as $setting ) {
+			if ( ! isset( $this->sections[ $setting->section ] ) )
+				continue;
+
+			$this->sections[ $setting->section ]->settings[] = $setting;
+
+			if ( $setting->check_capabilities() )
+				$setting->enqueue();
+		}
+
+		foreach ( $this->sections as $section ) {
+			usort( $section->settings, array( $this, '_cmp_priority' ) );
+		}
+	}
+
+	/**
+	 * Register some default controls.
+	 *
+	 * @since 3.4.0
+	 */
+	public function register_controls() {
+
+		/* Custom Header */
+
+		$this->add_section( 'header', array(
+			'title'          => __( 'Header' ),
+			'theme_supports' => 'custom-header',
+		) );
+
+		$this->add_setting( 'header_textcolor', array(
+			'label'             => 'Text Color',
+			'section'           => 'header',
+			'sanitize_callback' => 'sanitize_hexcolor',
+			'control'           => 'color',
+			'default'           => defined( 'HEADER_TEXTCOLOR' ) ? HEADER_TEXTCOLOR : ''
+		) );
+
+		/*
+		$this->add_setting( 'display_header', array(
+			'label'   => 'Display Text',
+			'section' => 'header',
+			'type'    => 'radio',
+			'choices' => array(
+				'show'  => 'Yes',
+				'hide'  => 'No'
+			),
+			// Showing header text is actually done by setting header_textcolor to 'blank'.
+			// @todo: Do some JS magic to make this work (since we'll be hiding the textcolor input).
+			'theme_mod' => false,
+		) );
+		*/
+
+		// Input type: checkbox
+		// With custom value
+		$this->add_setting( 'header_image', array(
+			'label'   => 'Random Image',
+			'section' => 'header',
+			'control' => 'checkbox',
+			 // @todo
+			 // not the default, it's the value.
+			 // value is saved in get_theme_support( 'custom-header' )[0][ 'random-default' ]
+			'default' => 'random-default-image'
+		) );
+
+		/* Custom Background */
+
+		$this->add_section( 'background', array(
+			'title'          => __( 'Background' ),
+			'theme_supports' => 'custom-background',
+		) );
+
+		// Input type: Color
+		// With sanitize_callback
+		$this->add_setting( 'background_color', array(
+			'label'             => 'Background Color',
+			'section'           => 'background',
+			'control'           => 'color',
+			'default'           => defined( 'BACKGROUND_COLOR' ) ? BACKGROUND_COLOR : '',
+			'sanitize_callback' => 'sanitize_hexcolor'
+		) );
+
+		/* Nav Menus */
+
+		$locations      = get_registered_nav_menus();
+		$menus          = wp_get_nav_menus();
+		$menu_locations = get_nav_menu_locations();
+		$num_locations  = count( array_keys( $locations ) );
+
+		$this->add_section( 'nav', array(
+			'title'          => __( 'Navigation' ),
+			'theme_supports' => 'menus',
+			'description'    => sprintf( _n('Your theme supports %s menu. Select which menu you would like to use.', 'Your theme supports %s menus. Select which menu appears in each location.', $num_locations ), number_format_i18n( $num_locations ) ),
+		) );
+
+		foreach ( $locations as $location => $description ) {
+			$choices = array( 0 => '' );
+			foreach ( $menus as $menu ) {
+				$truncated_name = wp_html_excerpt( $menu->name, 40 );
+				$truncated_name == $menu->name ? $menu->name : trim( $truncated_name ) . '&hellip;';
+				$choices[ $menu->term_id ] = $truncated_name;
+			}
+
+			$this->add_setting( "nav_menu_locations[{$location}]", array(
+				'label'             => $description,
+				'theme_supports'    => 'menus', // Todo: Needs also widgets -- array( 'menus', 'widgets' )
+				'section'           => 'nav',
+				'control'           => 'select',
+				'choices'           => $choices,
+				'sanitize_callback' => 'absint',
+			) );
+		}
+
+		/* Static Front Page */
+		// #WP19627
+
+		$this->add_section( 'static_front_page', array(
+			'title'          => __( 'Static Front Page' ),
+		//	'theme_supports' => 'static-front-page',
+			'description'    => __( 'Your theme supports a static front page.' ),
+		) );
+
+		$choices = array();
+		$choices['posts'] = __( 'Your latest posts' );
+		$choices['page'] = __( 'A static page (select below)' );
+
+		$this->add_setting( 'show_on_front', array(
+			'label'          => __( 'Front page displays' ),
+		//	'theme_supports' => 'static-front-page',
+			'section'        => 'static_front_page',
+			'control'        => 'radio',
+			'choices'        => $choices,
+			'default'        => get_option( 'show_on_front' ),
+			'type'           => 'option',
+			'capability'     => 'manage_options'
+		) );
+
+		$this->add_setting( 'page_on_front', array(
+			'label'          => __( 'Front page:' ),
+		//	'theme_supports' => 'static-front-page',
+			'section'        => 'static_front_page',
+			'control'        => 'dropdown-pages',
+			'type'           => 'option',
+			'capability'     => 'manage_options'
+		) );
+
+		$this->add_setting( 'page_for_posts', array(
+			'label'          => __( 'Posts page:' ),
+		//	'theme_supports' => 'static-front-page',
+			'section'        => 'static_front_page',
+			'control'        => 'dropdown-pages',
+			'type'           => 'option',
+			'capability'     => 'manage_options'
+		) );
+
+		/* Site Title & Tagline */
+
+		$this->add_section( 'strings', array(
+			'title'          => __( 'Site Title & Tagline' ),
+			'description'    => __( 'Customize some strings.' ),
+		) );
+
+		$this->add_setting( 'blogname', array(
+			'label'          => __( 'Site Title' ),
+			'section'        => 'strings',
+			'default'        => get_option( 'blogname' ),
+			'type'           => 'option',
+			'capability'     => 'manage_options'
+		) );
+
+		$this->add_setting( 'blogdescription', array(
+			'label'          => __( 'Tagline' ),
+			'section'        => 'strings',
+			'default'        => get_option( 'blogdescription' ),
+			'type'           => 'option',
+			'capability'     => 'manage_options'
+		) );
+	}
+};
+
+// Callback function for sanitizing a hex color
+function sanitize_hexcolor( $color ) {
+	$color = preg_replace( '/[^0-9a-fA-F]/', '', $color );
+
+	if ( preg_match('|[A-Fa-f0-9]{3,6}|', $color ) )
+		return $color;
+
+	return $color;
+}
+
+// Custome render type for a dropdown menu.
+function customize_control_dropdown_pages( $setting ) {
+	printf(
+		__( '<label>%s %s</label>' ),
+		$setting->label,
+		wp_dropdown_pages(
+			array(
+				'name'              => $setting->get_name(),
+				'echo'              => 0,
+				'show_option_none'  => __( '&mdash; Select &mdash;' ),
+				'option_none_value' => '0',
+				'selected'          => get_option( $setting->id )
+			)
+		)
+	);
+}
+add_action( 'customize_render_control-dropdown-pages', 'customize_control_dropdown_pages' );
diff --git a/wp-includes/css/customize-controls.css b/wp-includes/css/customize-controls.css
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wp-includes/css/customize-controls.dev.css b/wp-includes/css/customize-controls.dev.css
new file mode 100644
index 0000000000..295d2e47a6
--- /dev/null
+++ b/wp-includes/css/customize-controls.dev.css
@@ -0,0 +1,216 @@
+body {
+	overflow: hidden;
+}
+
+.customize-section {
+	border-top: 1px solid #fff;
+	border-bottom: 1px solid #dfdfdf;
+	padding: 15px 20px;
+	margin: 0;
+}
+
+.customize-section:last-child {
+	box-shadow: 0 1px 0 0px #fff;
+}
+
+#customize-controls {
+	width: 300px;
+	height: 100%;
+	padding: 0;
+	margin: 0;
+	z-index: 10;
+	position: relative;
+	overflow: auto;
+	background: #f5f5f5;
+	box-shadow: inset -11px 0 8px -8px rgba( 0, 0, 0, 0.1 );
+	border-right: 1px solid rgba( 0, 0, 0, 0.2 );
+}
+
+#customize-controls .theme-name {
+	font-size: 16px;
+	font-weight: bold;
+	line-height: 24px;
+	display: block;
+}
+
+#customize-controls .theme-screenshot {
+	width: 258px;
+	border: 1px solid #ccc;
+}
+
+#customize-controls .submit {
+	text-align: center;
+}
+
+#customize-info {
+	padding-top: 55px;
+}
+
+#customize-theme-controls {
+	padding-bottom: 60px;
+}
+
+#customize-theme-controls ul {
+	margin: 0;
+}
+
+#customize-theme-controls ul ul {
+	margin-top: 1em;
+	display: none;
+}
+
+#customize-theme-controls ul h3 {
+	margin: 0;
+	-webkit-user-select: none;
+	-moz-user-select: none;
+	user-select: none;
+}
+
+#customize-theme-controls ul h3:hover {
+	cursor: pointer;
+}
+
+#customize-theme-controls ul h3:after {
+	content: '';
+	border-color: #ccc transparent transparent transparent;
+	border-style: solid;
+	border-width: 6px;
+	float: right;
+	margin-top: 5px;
+	margin-left: 5px;
+}
+
+ #customize-theme-controls ul h3.open:after {
+	-moz-transform: rotate(180deg);
+	-webkit-transform: rotate(180deg);
+	-o-transform: rotate(180deg);
+	-ms-transform: rotate(180deg);
+	transform: rotate(180deg);
+	-moz-transform-origin: center 3px;
+	-webkit-transform-origin: center 3px;
+	-o-transform-origin: center 3px;
+	-ms-transform-origin: center 3px;
+	transform-origin: center 3px;
+}
+
+#customize-footer {
+	border-bottom: 0;
+	border-top: 1px solid #dfdfdf;
+	position: fixed;
+	bottom: 0;
+	left: 0;
+	width: 260px;
+	padding: 15px 20px;
+	margin: 0;
+	z-index: 10;
+	background: #f5f5f5;
+	box-shadow:
+		inset -11px 0 8px -8px rgba( 0, 0, 0, 0.1 ),
+		inset 0 1px 0 0px #fff,
+		0 0 11px 0 rgba( 0, 0, 0, 0.1 );
+}
+
+#customize-preview {
+	position: fixed;
+	left: 300px;
+	right: 0;
+	top: 0;
+	bottom: 0;
+}
+
+#customize-preview iframe {
+	width: 100%;
+	height: 100%;
+}
+
+.customize-loader {
+	background: transparent;
+	border: 4px solid #666;
+	border-radius: 50%;
+	display: block;
+	margin: 10px auto;
+	text-indent: -9999px;
+
+	height: 12px;
+	width: 12px;
+
+	/* Animation */
+	-webkit-animation: customize-loader 1s infinite ease-out;
+	-moz-animation: customize-loader 1s infinite ease-out;
+	animation: customize-loader 1s infinite ease-out;
+}
+@-moz-keyframes customize-loader {
+	0% {
+		opacity: 0;
+		-moz-transform: scale(0.7);
+	}
+	40% {
+		opacity: 1;
+	}
+	100% {
+		opacity: 0;
+		-moz-transform: scale(1);
+	}
+}
+@-webkit-keyframes customize-loader {
+	0% {
+		opacity: 0;
+		-webkit-transform: scale(0.7);
+	}
+	40% {
+		opacity: 1;
+	}
+	100% {
+		opacity: 0;
+		-webkit-transform: scale(1);
+	}
+}
+@keyframes customize-loader {
+	0% {
+		opacity: 0;
+		transform: scale(0.7);
+	}
+	40% {
+		opacity: 1;
+	}
+	100% {
+		opacity: 0;
+		transform: scale(1);
+	}
+}
+
+
+/*
+ * Style for custom settings
+ */
+.customize-section select {
+	max-width: 150px;
+}
+
+.customize-section .hex-prepend {
+	float: left;
+	display: block;
+	margin: 1px -2px 0 0;
+	line-height: 15px;
+	padding: 3px 5px;
+	color: #777;
+	text-align: center;
+	background-color: #fff;
+	border: 1px solid #dfdfdf;
+	-webkit-border-radius: 3px 0 0 3px;
+	border-radius: 3px 0 0 3px;
+}
+
+.customize-section input[type="text"].hex-input {
+	-webkit-border-radius: 0 3px 3px 0;
+	border-radius: 0 3px 3px 0;
+	width: 150px;
+}
+
+.customize-section .hex-color-example {
+	border: 1px solid #dfdfdf;
+	-webkit-border-radius: 3px;
+	border-radius: 3px;
+	padding: 3px 14px;
+	background-color: #ef45da
+}
diff --git a/wp-includes/css/customize-loader.css b/wp-includes/css/customize-loader.css
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wp-includes/css/customize-loader.dev.css b/wp-includes/css/customize-loader.dev.css
new file mode 100644
index 0000000000..536dc6995c
--- /dev/null
+++ b/wp-includes/css/customize-loader.dev.css
@@ -0,0 +1,90 @@
+body.customize-active {
+	overflow: hidden;
+}
+
+#customize-container {
+	display: none;
+	background: #fff;
+	z-index: 500000;
+	position: fixed;
+	top: 0;
+	bottom: 0;
+	left: 0;
+	right: 0;
+}
+
+.customize-active #customize-container {
+	display: block;
+}
+
+#customize-container.collapsed {
+	left: -302px;
+}
+
+#customize-container .collapse-sidebar,
+#customize-container .return-to-admin {
+	z-index: 50;
+}
+
+#customize-container div {
+	position: absolute;
+	left: 0;
+	top: 0;
+	width: 260px;
+	padding: 15px 20px;
+	background: #f5f5f5;
+	box-shadow:
+		inset -11px 0 8px -8px rgba( 0, 0, 0, 0.1 ),
+		inset 0 -1px 0 #dfdfdf,
+		-1px 1px 0 #fff;
+	border-right: 1px solid rgba( 0, 0, 0, 0.2 );
+}
+
+#customize-container iframe {
+	height: 100%;
+	width: 100%;
+	z-index: 20;
+}
+
+/* Collapse Button */
+#customize-container .collapse-sidebar {
+	position: absolute;
+	top: 13px;
+	left: 265px;
+	z-index: 50;
+	display: block;
+	width: 19px;
+	height: 19px;
+	padding: 0;
+	border-radius: 50%;
+}
+#customize-container.collapsed .collapse-sidebar {
+	position: absolute;
+	left: 315px;
+}
+#customize-container .collapse-sidebar span {
+	margin-top: 2px;
+	margin-left: 2px;
+	display: block;
+	width: 15px;
+	height: 15px;
+	background: transparent url('../../wp-admin/images/arrows.png') no-repeat 0 -72px;
+}
+#customize-container.collapsed .collapse-sidebar span {
+	background-position: 0 -108px;
+}
+
+/* Animations */
+#customize-container,
+#customize-container .collapse-sidebar {
+	-moz-transition-property: left, right, top, bottom;
+	-webkit-transition-property: left, right, top, bottom;
+	-o-transition-property: left, right, top, bottom;
+	-ms-transition-property: left, right, top, bottom;
+	transition-property: left, right, top, bottom;
+	-moz-transition-duration: 0.2s;
+	-webkit-transition-duration: 0.2s;
+	-o-transition-duration: 0.2s;
+	-ms-transition-duration: 0.2s;
+	transition-duration: 0.2s;
+}
diff --git a/wp-includes/customize-controls.php b/wp-includes/customize-controls.php
new file mode 100644
index 0000000000..599a53d141
--- /dev/null
+++ b/wp-includes/customize-controls.php
@@ -0,0 +1,108 @@
+<?php
+/**
+ * Customize Controls
+ *
+ * @package WordPress
+ * @subpackage Customize
+ * @since 3.4.0
+ */
+
+if ( ! defined( 'ABSPATH' ) )
+	die;
+
+global $wp_scripts;
+
+$registered = $wp_scripts->registered;
+$wp_scripts = new WP_Scripts;
+$wp_scripts->registered = $registered;
+
+add_action( 'customize_controls_print_scripts',        'print_head_scripts', 20 );
+add_action( 'customize_controls_print_footer_scripts', '_wp_footer_scripts'     );
+add_action( 'customize_controls_print_styles',         'print_admin_styles', 20 );
+
+do_action( 'customize_controls_init' );
+
+wp_enqueue_script( 'customize-controls' );
+wp_enqueue_style( 'customize-controls' );
+
+do_action( 'customize_controls_enqueue_scripts' );
+
+$theme = get_theme( get_current_theme() );
+
+if ( $theme['Screenshot'] )
+	$screenshot = $theme['Theme Root URI'] . '/' . $theme['Stylesheet'] . '/' . $theme['Screenshot'];
+else
+	$screenshot = '';
+
+// Let's roll.
+@header('Content-Type: ' . get_option('html_type') . '; charset=' . get_option('blog_charset'));
+
+wp_user_settings();
+_wp_admin_html_begin();
+
+$admin_title = sprintf( __( '%1$s &#8212; WordPress' ), strip_tags( sprintf( __( 'Customize %s' ), $theme['Name'] ) ) );
+?><title><?php echo $admin_title; ?></title><?php
+
+do_action( 'customize_controls_print_styles' );
+do_action( 'customize_controls_print_scripts' );
+?>
+</head>
+<body>
+	<form id="customize-controls" method="post" class="wrap" target="_parent" action="<?php echo esc_url( add_query_arg( 'save', '1', admin_url( 'themes.php' ) ) ); ?>">
+		<?php wp_nonce_field( 'customize_controls' ); ?>
+		<input type="hidden" name="customize" value="on" />
+		<input type="hidden" id="customize-template" name="template" value="<?php echo esc_attr( $theme['Template'] ); ?>" />
+		<input type="hidden" id="customize-stylesheet" name="stylesheet" value="<?php echo esc_attr( $theme['Stylesheet'] ); ?>" />
+
+		<div id="customize-info" class="customize-section">
+			<p>
+				<strong class="theme-name"><?php echo $theme['Name']; ?></strong>
+				<span class="theme-by"><?php printf( __( 'By %s' ), $theme['Author'] ); ?></span>
+			</p>
+			<?php if ( $screenshot ) : ?>
+				<img class="theme-screenshot" src="<?php echo esc_url( $screenshot ); ?>" />
+			<?php endif; ?>
+		</div>
+
+		<div id="customize-theme-controls"><ul>
+			<?php
+			foreach ( $this->sections as $section )
+				$section->render();
+			?>
+		</ul></div>
+
+		<div id="customize-footer" class="customize-section">
+			<?php
+			submit_button( __( 'Refresh' ), 'secondary', 'refresh', false );
+			submit_button( __( 'Save' ), 'primary', 'save', false );
+			?>
+		</div>
+	</form>
+	<div id="customize-preview">
+		<iframe name="customize-target"></iframe>
+	</div>
+	<?php
+
+	do_action( 'customize_controls_print_footer_scripts' );
+
+	$settings = array(
+		'preview' => esc_url( home_url( '/' ) ),
+		'values'  => array(),
+		'prefix'  => WP_Customize_Setting::name_prefix,
+	);
+
+	foreach ( $this->settings as $id => $setting ) {
+		$settings['values'][ $id ] = $setting->value();
+	}
+
+	?>
+	<script type="text/javascript">
+		(function() {
+			if ( typeof wp === 'undefined' || ! wp.customize )
+				return;
+
+			wp.customize.settings = <?php echo json_encode( $settings ); ?>;
+		})();
+	</script>
+</body>
+</html>
diff --git a/wp-includes/js/customize-base.dev.js b/wp-includes/js/customize-base.dev.js
new file mode 100644
index 0000000000..5b5a67fd9c
--- /dev/null
+++ b/wp-includes/js/customize-base.dev.js
@@ -0,0 +1,496 @@
+if ( typeof wp === 'undefined' )
+	var wp = {};
+
+(function( exports, $ ){
+	var api, extend, ctor, inherits, ready,
+		slice = Array.prototype.slice;
+
+	/* =====================================================================
+	 * Micro-inheritance - thank you, backbone.js.
+	 * ===================================================================== */
+
+	extend = function( protoProps, classProps ) {
+		var child = inherits( this, protoProps, classProps );
+		child.extend = this.extend;
+		return child;
+	};
+
+	// Shared empty constructor function to aid in prototype-chain creation.
+	ctor = function() {};
+
+	// Helper function to correctly set up the prototype chain, for subclasses.
+	// Similar to `goog.inherits`, but uses a hash of prototype properties and
+	// class properties to be extended.
+	inherits = function( parent, protoProps, staticProps ) {
+		var child;
+
+		// The constructor function for the new subclass is either defined by you
+		// (the "constructor" property in your `extend` definition), or defaulted
+		// by us to simply call `super()`.
+		if ( protoProps && protoProps.hasOwnProperty( 'constructor' ) ) {
+			child = protoProps.constructor;
+		} else {
+			child = function() {
+				// Storing the result `super()` before returning the value
+				// prevents a bug in Opera where, if the constructor returns
+				// a function, Opera will reject the return value in favor of
+				// the original object. This causes all sorts of trouble.
+				var result = parent.apply( this, arguments );
+				return result;
+			};
+		}
+
+		// Inherit class (static) properties from parent.
+		$.extend( child, parent );
+
+		// Set the prototype chain to inherit from `parent`, without calling
+		// `parent`'s constructor function.
+		ctor.prototype  = parent.prototype;
+		child.prototype = new ctor();
+
+		// Add prototype properties (instance properties) to the subclass,
+		// if supplied.
+		if ( protoProps )
+			$.extend( child.prototype, protoProps );
+
+		// Add static properties to the constructor function, if supplied.
+		if ( staticProps )
+			$.extend( child, staticProps );
+
+		// Correctly set child's `prototype.constructor`.
+		child.prototype.constructor = child;
+
+		// Set a convenience property in case the parent's prototype is needed later.
+		child.__super__ = parent.prototype;
+
+		return child;
+	};
+
+	/* =====================================================================
+	 * customize function.
+	 * ===================================================================== */
+	ready = $.Callbacks( 'once memory' );
+
+	/*
+	 * Sugar for main customize function. Supports several signatures.
+	 *
+	 * customize( callback, [context] );
+	 *   Binds a callback to be fired when the customizer is ready.
+	 *   - callback, function
+	 *   - context, object
+	 *
+	 * customize( setting );
+	 *   Fetches a setting object by ID.
+	 *   - setting, string - The setting ID.
+	 *
+	 */
+	api = {};
+	// api = function( callback, context ) {
+	// 	if ( $.isFunction( callback ) ) {
+	// 		if ( context )
+	// 			callback = $.proxy( callback, context );
+	// 		ready.add( callback );
+	//
+	// 		return api;
+	// 	}
+	// }
+
+	/* =====================================================================
+	 * Base class.
+	 * ===================================================================== */
+
+	api.Class = function( applicator, argsArray, options ) {
+		var magic, args = arguments;
+
+		if ( applicator && argsArray && api.Class.applicator === applicator ) {
+			args = argsArray;
+			$.extend( this, options || {} );
+		}
+
+		magic = this;
+		if ( this.instance ) {
+			magic = function() {
+				return magic.instance.apply( magic, arguments );
+			};
+
+			$.extend( magic, this );
+		}
+
+		magic.initialize.apply( magic, args );
+		return magic;
+	};
+
+	api.Class.applicator = {};
+
+	api.Class.prototype.initialize = function() {};
+
+	/*
+	 * Checks whether a given instance extended a constructor.
+	 *
+	 * The magic surrounding the instance parameter causes the instanceof
+	 * keyword to return inaccurate results; it defaults to the function's
+	 * prototype instead of the constructor chain. Hence this function.
+	 */
+	api.Class.prototype.extended = function( constructor ) {
+		var proto = this;
+
+		while ( typeof proto.constructor !== 'undefined' ) {
+			if ( proto.constructor === constructor )
+				return true;
+			if ( typeof proto.constructor.__super__ === 'undefined' )
+				return false;
+			proto = proto.constructor.__super__;
+		}
+		return false;
+	};
+
+	api.Class.extend = extend;
+
+	/* =====================================================================
+	 * Light two-way binding.
+	 * ===================================================================== */
+
+	api.Value = api.Class.extend({
+		initialize: function( initial, options ) {
+			this._value = initial;
+			this.callbacks = $.Callbacks();
+
+			$.extend( this, options || {} );
+		},
+
+		/*
+		 * Magic. Returns a function that will become the instance.
+		 * Set to null to prevent the instance from extending a function.
+		 */
+		instance: function() {
+			return arguments.length ? this.set.apply( this, arguments ) : this.get();
+		},
+
+		get: function() {
+			return this._value;
+		},
+
+		set: function( to ) {
+			var from = this._value;
+
+			to = this.validate( to );
+
+			// Bail if the sanitized value is null or unchanged.
+			if ( null === to || this._value === to )
+				return this;
+
+			this._value = to;
+
+			this.callbacks.fireWith( this, [ to, from ] );
+
+			return this;
+		},
+
+		validate: function( value ) {
+			return value;
+		},
+
+		bind: function( callback ) {
+			this.callbacks.add.apply( this.callbacks, arguments );
+			return this;
+		},
+
+		unbind: function( callback ) {
+			this.callbacks.remove.apply( this.callbacks, arguments );
+			return this;
+		},
+
+		/*
+		 * Allows the creation of composite values.
+		 * Overrides the native link method (can be reverted with `unlink`).
+		 */
+		link: function() {
+			var keys = slice.call( arguments ),
+				callback = keys.pop(),
+				self = this,
+				set, key, active;
+
+			if ( this.links )
+				this.unlink();
+
+			this.links = [];
+
+			// Single argument means a direct binding.
+			if ( ! keys.length ) {
+				keys = [ callback ];
+				callback = function( value, to ) {
+					return to;
+				};
+			}
+
+			while ( key = keys.shift() ) {
+				if ( this._parent && $.type( key ) == 'string' )
+					this.links.push( this._parent[ key ] );
+				else
+					this.links.push( key );
+			}
+
+			// Replace this.set with the assignment function.
+			set = function() {
+				var args, result;
+
+				// If we call set from within the assignment function,
+				// pass the arguments to the original set.
+				if ( active )
+					return self.set.original.apply( self, arguments );
+
+				active = true;
+
+				args = self.links.concat( slice.call( arguments ) );
+				result = callback.apply( self, args );
+
+				active = false;
+
+				if ( typeof result !== 'undefined' )
+					self.set.original.call( self, result );
+			};
+
+			set.original = this.set;
+			this.set = set;
+
+			// Bind the new function to the master values.
+			$.each( this.links, function( key, value ) {
+				value.bind( self.set );
+			});
+
+			this.set( this.get() );
+
+			return this;
+		},
+
+		unlink: function() {
+			var set = this.set;
+
+			$.each( this.links, function( key, value ) {
+				value.unbind( set );
+			});
+
+			delete this.links;
+			this.set = this.set.original;
+			return this;
+		}
+	});
+
+	api.ensure = function( element ) {
+		return typeof element == 'string' ? $( element ) : element;
+	};
+
+	sync = {
+		'val': {
+			update: function() {
+				this.element[ this._updater ]( this._value );
+			},
+			refresh: function() {
+				this.set( this.element[ this._refresher ]() );
+			}
+		}
+	}
+
+	api.Element = api.Value.extend({
+		initialize: function( element, options ) {
+			var synchronizer = api.Element.synchronizer.html,
+				type;
+
+			this.element = api.ensure( element );
+			this.events = '';
+
+			if ( this.element.is('input, select, textarea') ) {
+				this.events += 'change';
+				synchronizer = api.Element.synchronizer.val;
+
+				if ( this.element.is('input') ) {
+					type = this.element.prop('type');
+					if ( api.Element.synchronizer[ type ] )
+						synchronizer = api.Element.synchronizer[ type ];
+					if ( 'text' === type || 'password' === type )
+						this.events += ' keyup';
+				}
+			}
+
+			api.Value.prototype.initialize.call( this, null, $.extend( options || {}, synchronizer ) );
+			this._value = this.get();
+
+			this.bind( this.update );
+
+			this.refresh = $.proxy( this.refresh, this );
+			this.element.bind( this.events, this.refresh );
+		},
+
+		find: function( selector ) {
+			return $( selector, this.element );
+		},
+
+		refresh: function() {},
+		update: function() {}
+	});
+
+	api.Element.synchronizer = {};
+
+	$.each( [ 'html', 'val' ], function( i, method ) {
+		api.Element.synchronizer[ method ] = {
+			update: function( to ) {
+				this.element[ method ]( to );
+			},
+			refresh: function() {
+				this.set( this.element[ method ]() );
+			}
+		};
+	});
+
+	api.Element.synchronizer.checkbox = {
+		update: function( to ) {
+			this.element.prop( 'checked', to );
+		},
+		refresh: function() {
+			this.set( this.element.prop( 'checked' ) );
+		}
+	};
+
+	api.Element.synchronizer.radio = {
+		update: function( to ) {
+			this.element.filter( function() {
+				return this.value === to;
+			}).prop( 'checked', true );
+		},
+		refresh: function() {
+			this.set( this.element.filter( ':checked' ).val() );
+		}
+	};
+
+	api.ValueFactory = function( constructor ) {
+		constructor = constructor || api.Value;
+
+		return function( key ) {
+			var args = slice.call( arguments, 1 );
+			this[ key ] = new constructor( api.Class.applicator, args );
+			this[ key ]._parent = this;
+			return this[ key ];
+		};
+	};
+
+	api.Values = api.Value.extend({
+		defaultConstructor: api.Value,
+
+		initialize: function( options ) {
+			api.Value.prototype.initialize.call( this, {}, options || {} );
+		},
+
+		instance: function( id ) {
+			return this.value( id );
+		},
+
+		value: function( id ) {
+			return this._value[ id ];
+		},
+
+		has: function( id ) {
+			return typeof this._value[ id ] !== 'undefined';
+		},
+
+		add: function( id, value ) {
+			if ( this.has( id ) )
+				return;
+
+			this._value[ id ] = value;
+			this._value[ id ]._parent = this._value;
+			return this._value[ id ];
+		},
+
+		set: function( id ) {
+			if ( this.has( id ) )
+				return this.pass( 'set', arguments );
+
+			return this.add( id, new this.defaultConstructor( api.Class.applicator, slice.call( arguments, 1 ) ) );
+		},
+
+		remove: function( id ) {
+			delete this._value[ id ];
+		},
+
+		pass: function( fn, args ) {
+			var id, value;
+
+			args = slice.call( args );
+			id   = args.shift();
+
+			if ( ! this.has( id ) )
+				return;
+
+			value = this.value( id );
+			return value[ fn ].apply( value, args );
+		}
+	});
+
+	$.each( [ 'get', 'bind', 'unbind', 'link', 'unlink' ], function( i, method ) {
+		api.Values.prototype[ method ] = function() {
+			return this.pass( method, arguments );
+		};
+	});
+
+	/* =====================================================================
+	 * Messenger for postMessage.
+	 * ===================================================================== */
+
+	api.Messenger = api.Class.extend({
+		add: api.ValueFactory(),
+
+		initialize: function( url, options ) {
+			$.extend( this, options || {} );
+
+			this.add( 'url', url );
+			this.add( 'origin' ).link( 'url', function( url ) {
+				return url().replace( /([^:]+:\/\/[^\/]+).*/, '$1' );
+			});
+
+			this.topics = {};
+
+			$.receiveMessage( $.proxy( this.receive, this ), this.origin() || null );
+		},
+		receive: function( event ) {
+			var message;
+
+			console.log( 'messenger receiveMessage', arguments );
+
+			// @todo: remove, this is done in the postMessage plugin.
+			// if ( this.origin && event.origin !== this.origin )
+			// 	return;
+
+			message = JSON.parse( event.data );
+
+			if ( message && message.id && message.data && this.topics[ message.id ] )
+				this.topics[ message.id ].fireWith( this, [ message.data ]);
+		},
+		send: function( id, data ) {
+			var message;
+
+			if ( ! this.url() )
+				return;
+
+			console.log( 'sending message', id, data );
+			message = JSON.stringify({ id: id, data: data });
+			$.postMessage( message, this.url(), this.targetWindow || null );
+		},
+		bind: function( id, callback ) {
+			var topic = this.topics[ id ] || ( this.topics[ id ] = $.Callbacks() );
+			topic.add( callback );
+		},
+		unbind: function( id, callback ) {
+			if ( this.topics[ id ] )
+				this.topics[ id ].remove( callback );
+		}
+	});
+
+	/* =====================================================================
+	 * Core customize object.
+	 * ===================================================================== */
+
+	api = $.extend( new api.Values(), api );
+
+	// Expose the API to the world.
+	exports.customize = api;
+})( wp, jQuery );
diff --git a/wp-includes/js/customize-base.js b/wp-includes/js/customize-base.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wp-includes/js/customize-controls.dev.js b/wp-includes/js/customize-controls.dev.js
new file mode 100644
index 0000000000..40f46ff40d
--- /dev/null
+++ b/wp-includes/js/customize-controls.dev.js
@@ -0,0 +1,101 @@
+(function( exports, $ ){
+	var api = wp.customize;
+
+	api.Previewer = api.Messenger.extend({
+		/**
+		 * Requires params:
+		 *  - iframe - a selector or jQuery element
+		 *  - form   - a selector or jQuery element
+		 *  - url    - the URL of preview frame
+		 */
+		initialize: function( params, options ) {
+			$.extend( this, options || {} );
+
+			this.iframe = api.ensure( params.iframe );
+			this.form   = api.ensure( params.form );
+
+			api.Messenger.prototype.initialize.call( this, params.url, {
+				targetWindow: this.iframe[0].contentWindow
+			});
+
+			this._formOriginalProps = {
+				target: this.form.prop('target'),
+				action: this.form.prop('action')
+			};
+
+			this.bind( 'url', function( url ) {
+				// Bail if we're navigating to the current url, to a different origin, or wp-admin.
+				if ( this.url() == url || 0 !== url.indexOf( this.origin() + '/' ) || -1 !== url.indexOf( 'wp-admin' )  )
+					return;
+
+				this.url( url );
+				this.refresh();
+			});
+
+			this.refresh();
+		},
+		refresh: function() {
+			this.submit({
+				target: this.iframe.prop('name'),
+				action: this.url()
+			});
+		},
+		submit: function( props ) {
+			if ( props )
+				this.form.prop( props );
+			this.form.submit();
+			if ( props )
+				this.form.prop( this._formOriginalProps );
+		}
+	});
+
+	/* =====================================================================
+	 * Ready.
+	 * ===================================================================== */
+
+	$( function() {
+		var previewer,
+			controls = $('[name^="' + api.settings.prefix + '"]');
+
+		// Initialize Previewer
+		previewer = new api.Previewer({
+			iframe: '#customize-preview iframe',
+			form:   '#customize-controls',
+			url:    api.settings.preview
+		});
+
+		$.each( api.settings.values, function( id, value ) {
+			var elements = controls.filter( '[name="' + api.settings.prefix + id + '"]' ),
+				setting = api.set( id, value );
+
+			setting.control = new wp.customize.Element( elements );
+
+			setting.control.link( setting );
+			setting.link( setting.control );
+		});
+
+		// Temporary accordion code.
+		$('.control-section h3').click( function() {
+			$( this ).siblings('ul').slideToggle( 200 );
+			$( this ).toggleClass( 'open' );
+			return false;
+		});
+
+		// Button bindings.
+		$('#save').click( function() {
+			previewer.submit();
+			return false;
+		});
+
+		$('#refresh').click( function() {
+			previewer.refresh();
+			return false;
+		});
+
+		// Fetch prefixed settings.
+		$('[name^="' + api.settings.prefix + '"]').each( function() {
+			// console.log( this.name );
+		});
+	});
+
+})( wp, jQuery );
\ No newline at end of file
diff --git a/wp-includes/js/customize-controls.js b/wp-includes/js/customize-controls.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wp-includes/js/customize-loader.dev.js b/wp-includes/js/customize-loader.dev.js
new file mode 100644
index 0000000000..beba0332b8
--- /dev/null
+++ b/wp-includes/js/customize-loader.dev.js
@@ -0,0 +1,75 @@
+if ( typeof wp === 'undefined' )
+	var wp = {};
+
+(function( exports, $ ){
+	var Loader = {
+		initialize: function() {
+			this.body      = $( document.body );
+			this.element   = $( '#customize-container' );
+			this.base      = $( '.admin-url', this.element ).val();
+			this.doc_title = $( document ).attr( 'title' );
+
+			this.element.on( 'click', '.return-to-admin', function() {
+				Loader.close();
+				return false;
+			});
+
+			this.element.on( 'click', '.collapse-sidebar', function() {
+				Loader.element.toggleClass('collapsed');
+				return false;
+			});
+		},
+		open: function( params ) {
+			params.customize = 'on';
+
+			this.element.append( '<iframe />' );
+			this.iframe = $( 'iframe' ).attr( 'src', this.base + '?' + jQuery.param( params ) );
+
+			$('iframe').load( function() {
+				title = $(this).contents().find( 'title' ).text();
+				$( document ).attr( 'title', title );
+			});
+
+			this.element.fadeIn( 200, function() {
+				Loader.body.addClass( 'customize-active' );
+			});
+		},
+		close: function() {
+			this.element.fadeOut( 200, function() {
+				Loader.iframe.remove();
+				Loader.iframe = null;
+				Loader.body.removeClass( 'customize-active' );
+				$( document ).attr( 'title', Loader.doc_title );
+			});
+		}
+	};
+
+	$( function() {
+		Loader.initialize();
+
+		// Override 'preview' links on themes page.
+		$('.thickbox-preview').click( function( event ) {
+			var href, template, stylesheet;
+
+			// Stop the thickbox.
+			event.preventDefault();
+			event.stopImmediatePropagation();
+
+			// Extract the template/stylesheet from the preview link's url.
+			href = $(this).attr('href');
+			template = href.match('template=([^&]*)')[1];
+			stylesheet = href.match('stylesheet=([^&]*)')[1];
+
+			// Load the theme.
+			Loader.open({
+				template: template,
+				stylesheet: stylesheet
+			});
+		}).filter( function() {
+			return 'Preview' == $(this).text();
+		}).text('Customize');
+	});
+
+	// Expose the API to the world.
+	exports.CustomizeLoader = Loader;
+})( wp, jQuery );
diff --git a/wp-includes/js/customize-loader.js b/wp-includes/js/customize-loader.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wp-includes/js/customize-preview.dev.js b/wp-includes/js/customize-preview.dev.js
new file mode 100644
index 0000000000..8e46a9c64f
--- /dev/null
+++ b/wp-includes/js/customize-preview.dev.js
@@ -0,0 +1,59 @@
+(function( exports, $ ){
+	var api = wp.customize;
+
+	api.Preview = api.Messenger.extend({
+		/**
+		 * Requires params:
+		 *  - url    - the URL of preview frame
+		 *
+		 * @todo: Perhaps add a window.onbeforeunload dialog in case the theme
+		 *        somehow attempts to leave the page and we don't catch it
+		 *        (which really shouldn't happen).
+		 */
+		initialize: function( url, options ) {
+			var self = this;
+
+			$.extend( this, options || {} );
+
+			api.Messenger.prototype.initialize.call( this, url );
+
+			this.body = $( document.body );
+			this.body.on( 'click.preview', 'a', function( event ) {
+				event.preventDefault();
+				self.send( 'url', $(this).attr('href') );
+			});
+
+			// You cannot submit forms.
+			// @todo: Namespace customizer settings so that we can mix the
+			//        $_POST data with the customize setting $_POST data.
+			this.body.on( 'submit.preview', 'form', function( event ) {
+				event.preventDefault();
+			});
+
+			this.bind( 'url', function( url ) {
+				this.url( url );
+				this.refresh();
+			});
+		},
+		refresh: function() {
+			this.submit({
+				target: this.iframe.prop('name'),
+				action: this.url()
+			});
+		},
+		submit: function( props ) {
+			if ( props )
+				this.form.prop( props );
+			this.form.submit();
+			if ( props )
+				this.form.prop( this._formOriginalProps );
+		}
+	});
+
+	$( function() {
+		var preview;
+
+		preview = new api.Preview( api.settings.parent );
+	});
+
+})( wp, jQuery );
\ No newline at end of file
diff --git a/wp-includes/js/customize-preview.js b/wp-includes/js/customize-preview.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/wp-includes/script-loader.php b/wp-includes/script-loader.php
index f6cd1f6ec8..4969943c32 100644
--- a/wp-includes/script-loader.php
+++ b/wp-includes/script-loader.php
@@ -289,6 +289,11 @@ function wp_default_scripts( &$scripts ) {
 
 	$scripts->add( 'hoverIntent', "/wp-includes/js/hoverIntent$suffix.js", array('jquery'), 'r6', 1 );
 
+	$scripts->add( 'customize-loader', "/wp-includes/js/customize-loader$suffix.js",   array( 'jquery' ), false, 1 );
+	$scripts->add( 'customize-base', "/wp-includes/js/customize-base$suffix.js",       array( 'jquery-postmessage', 'json2' ), false, 1 );
+	$scripts->add( 'customize-controls', "/wp-includes/js/customize-controls$suffix.js", array( 'customize-base' ), false, 1 );
+	$scripts->add( 'customize-preview', "/wp-includes/js/customize-preview$suffix.js",  array( 'customize-base' ), false, 1 );
+
 	if ( is_admin() ) {
 		$scripts->add( 'ajaxcat', "/wp-admin/js/cat$suffix.js", array( 'wp-lists' ) );
 		$scripts->add_data( 'ajaxcat', 'group', 1 );
@@ -464,6 +469,8 @@ function wp_default_styles( &$styles ) {
 	$styles->add( 'wp-jquery-ui-dialog', "/wp-includes/css/jquery-ui-dialog$suffix.css" );
 	$styles->add( 'editor-buttons', "/wp-includes/css/editor-buttons$suffix.css" );
 	$styles->add( 'wp-pointer', "/wp-includes/css/wp-pointer$suffix.css" );
+	$styles->add( 'customize-loader', "/wp-includes/css/customize-loader$suffix.css" );
+	$styles->add( 'customize-controls', "/wp-includes/css/customize-controls$suffix.css", array( 'wp-admin', 'colors', 'ie' ) );
 
 	foreach ( $rtl_styles as $rtl_style ) {
 		$styles->add_data( $rtl_style, 'rtl', true );
diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index 1fcbd979f1..6ebcafb876 100644
--- a/wp-includes/theme.php
+++ b/wp-includes/theme.php
@@ -2082,3 +2082,15 @@ function check_theme_switched() {
 		update_option( 'theme_switched', false );
 	}
 }
+
+function wp_customize_load() {
+	// Load on themes.php or ?customize=on
+	if ( ! ( isset( $_REQUEST['customize'] ) && 'on' == $_REQUEST['customize'] ) && 'themes.php' != $GLOBALS['pagenow'] )
+		return;
+
+	require( ABSPATH . WPINC . '/class-wp-customize.php' );
+	// Init Customize class
+	// @todo Dependency injection instead
+	$GLOBALS['customize'] = new WP_Customize;
+}
+add_action( 'plugins_loaded', 'wp_customize_load' );