diff -urp wysiwyg_original/editors/js/yui.js wysiwyg_new/editors/js/yui.js
--- wysiwyg_original/editors/js/yui.js	2008-12-08 19:58:09.000000000 +0100
+++ wysiwyg_new/editors/js/yui.js	2009-10-26 02:46:52.000000000 +0100
@@ -1,13 +1,43 @@
 // $Id: yui.js,v 1.1 2008/12/08 18:58:09 sun Exp $
 
 /**
+ * Initialize editor instances.
+ */
+Drupal.wysiwyg.editor.init.yui = function(settings) {
+  // Initialize editor configurations.
+};
+
+/**
  * Attach this editor to a target element.
  */
 Drupal.wysiwyg.editor.attach.yui = function(context, params, settings) {
   // Apply theme.
   $('#' + params.field).parent().addClass('yui-skin-' + settings.theme);
+  
+	// Import plugins CSS.
+  if (Drupal.settings.wysiwyg.plugins[params.format]) {
+	  for (var plugin in Drupal.settings.wysiwyg.plugins[params.format].drupal) {
+	  	console.log(Drupal.settings.wysiwyg.plugins[params.format].drupal[plugin]);
+	  	if (Drupal.settings.wysiwyg.plugins[params.format].drupal[plugin].css) {
+	  		settings.extracss = settings.extracss+' @import "'+Drupal.settings.wysiwyg.plugins[params.format].drupal[plugin].css+'"; ';
+	  	}
+	  }
+  }
+  
   // Attach editor.
   var editor = new YAHOO.widget.Editor(params.field, settings);
+	
+	// Create plugins buttons.
+  if (Drupal.settings.wysiwyg.plugins[params.format]) {
+  	editor.on('toolbarLoaded', function() {
+  		// Create a group for extra plugins.
+			editor.toolbar.addButtonGroup({ group: 'plugins', buttons: [] });
+      // Load Drupal plugins.
+      for (var plugin in Drupal.settings.wysiwyg.plugins[params.format].drupal) {
+        Drupal.wysiwyg.editor.instance.yui.addPlugin(plugin, Drupal.settings.wysiwyg.plugins[params.format].drupal[plugin], Drupal.settings.wysiwyg.plugins.drupal[plugin], params.field);
+      }
+  	});
+  }
   editor.render();
 };
 
@@ -30,9 +60,57 @@ Drupal.wysiwyg.editor.detach.yui = funct
       var instance = YAHOO.widget.EditorInfo._instances[e];
       instance.saveHTML();
       instance.destroy();
-      // Remove all editor instances.
-      //nicEditors.editors[e].nicInstances = [];
     }
   }
 };
 
+Drupal.wysiwyg.editor.instance.yui = {
+  addPlugin: function(plugin, settings, pluginSettings, instanceId) {
+
+    if (typeof Drupal.wysiwyg.plugins[plugin] != 'object') {
+      return;
+    }
+
+		var editor = YAHOO.widget.EditorInfo._instances[instanceId];
+		
+    var button = { 
+	    type: settings.type, 
+	    label: settings.iconTitle, 
+	    value: plugin, 
+	    disabled: false
+    };
+    editor.toolbar.addButtonToGroup(button, 'plugins');
+    
+    var buttons = editor.toolbar.getButtons();
+    var lastButton = buttons[buttons.length-1];
+		$(lastButton._button).parent().css('background', 'transparent url('+settings.icon+') no-repeat center');
+		
+    editor.toolbar.on(plugin+'Click', function(o) {
+    	editor._createCurrentElement('span');
+			var data = { format: 'html', node: editor.currentElement[0], content: $(editor.currentElement[0]).html() };
+      Drupal.wysiwyg.plugins[plugin].invoke(data, pluginSettings, instanceId);
+	  }, editor, true);
+  },
+
+  openDialog: function(dialog, params) {
+
+  },
+
+  closeDialog: function(dialog) {
+
+  },
+
+  prepareContent: function(content) {
+    return content;
+  },
+
+  insert: function(content) {
+  	var editor = YAHOO.widget.EditorInfo._instances[this.field];
+		editor.execCommand('inserthtml', content);
+  },
+
+  getContent: function() {
+
+  }
+};
+
diff -urp wysiwyg_original/editors/yui.inc wysiwyg_new/editors/yui.inc
--- wysiwyg_original/editors/yui.inc	2009-10-23 05:00:56.000000000 +0200
+++ wysiwyg_new/editors/yui.inc	2009-10-26 02:54:06.000000000 +0100
@@ -46,6 +46,14 @@ function wysiwyg_yui_editor() {
     'load callback' => 'wysiwyg_yui_load',
     'settings callback' => 'wysiwyg_yui_settings',
     'plugin callback' => 'wysiwyg_yui_plugins',
+    'plugin settings callback' => 'wysiwyg_yui_plugin_settings',
+    'proxy plugin' => array(
+      'drupal' => array(
+        'load' => TRUE,
+        'proxy' => TRUE,
+      ),
+    ),
+    'proxy plugin settings callback' => 'wysiwyg_yui_proxy_plugin_settings',
     'versions' => array(
       '2.7.0' => array(
         'js files' => array('yui.js'),
@@ -187,7 +195,9 @@ function wysiwyg_yui_settings($editor, $
             array('text' => 'Verdana'),
           ));
         }
-        $buttons[] = wysiwyg_yui_button_setting($editor, $plugin, $button, $extra);
+        if ($plugin == 'default') {
+        	$buttons[] = wysiwyg_yui_button_setting($editor, $plugin, $button, $extra);
+        }
       }
     }
     // Group buttons in a dummy group.
@@ -209,7 +219,6 @@ function wysiwyg_yui_settings($editor, $
       $settings['extracss'] = '@import "' . implode('"; @import "', $settings['extracss']) . '";';
     }
   }
-
   return $settings;
 }
 
@@ -230,8 +239,7 @@ function wysiwyg_yui_button_setting($edi
   static $plugins;
 
   if (!isset($plugins)) {
-    // @todo Invoke all enabled plugins, not just internals.
-    $plugins = wysiwyg_yui_plugins($editor);
+    $plugins = wysiwyg_get_plugins($editor['name']);
   }
 
   // Return a simple separator.
@@ -267,6 +275,41 @@ function wysiwyg_yui_button_setting($edi
 }
 
 /**
+ * Build a JS settings array of native external plugins that need to be loaded separately.
+*/
+function wysiwyg_yui_plugin_settings($editor, $profile, $plugins) {
+  $settings = array();
+  foreach ($plugins as $name => $plugin) {
+    if (!empty($plugin['load'])) {
+      // Add path for native external plugins; internal ones are loaded
+      // automatically.
+      if (empty($plugin['internal']) && isset($plugin['path'])) {
+        $settings[$name] = base_path() . $plugin['path'];
+      }
+    }
+  }
+  return $settings;
+}
+
+/**
+ * Build a JS settings array for Drupal plugins loaded via the proxy plugin.
+ */
+function wysiwyg_yui_proxy_plugin_settings($editor, $profile, $plugins) {
+  $settings = array();
+  foreach ($plugins as $name => $plugin) {
+    // Populate required plugin settings.
+    $settings[$name] = $plugin['dialog settings'] + array(
+      'title' => $plugin['title'],
+      'icon' => base_path() . $plugin['icon path'] . '/' . $plugin['icon file'],
+      'iconTitle' => $plugin['icon title'],
+      // @todo These should only be set if the plugin defined them.
+      'css' => base_path() . $plugin['css path'] . '/' . $plugin['css file'],
+    );
+  }
+  return $settings;
+}
+
+/**
  * Return internal plugins for this editor; semi-implementation of hook_wysiwyg_plugin().
  */
 function wysiwyg_yui_plugins($editor) {