diff --git a/composer.json b/composer.json
index 6a5c383..b797b2f 100644
--- a/composer.json
+++ b/composer.json
@@ -70,6 +70,7 @@
 		"php": ">=5.3.0",
 		"michelf/php-markdown": "1.3",
 		"twig/twig": "1.12.*",
-		"smarty/smarty": "3.1.*"
+		"smarty/smarty": "3.1.*",
+		"ezyang/htmlpurifier": "v4.5.0"
 	}
 }
diff --git a/composer.lock b/composer.lock
new file mode 100644
index 0000000..c269cf3
--- /dev/null
+++ b/composer.lock
@@ -0,0 +1,212 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at http://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file"
+    ],
+    "hash": "8036953eff9eafbdbd4c431929a1d223",
+    "packages": [
+        {
+            "name": "ezyang/htmlpurifier",
+            "version": "v4.5.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/ezyang/htmlpurifier.git",
+                "reference": "v4.5.0"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/ezyang/htmlpurifier/zipball/v4.5.0",
+                "reference": "v4.5.0",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.2"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-0": {
+                    "HTMLPurifier": "library/"
+                },
+                "files": [
+                    "library/HTMLPurifier.composer.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "LGPL"
+            ],
+            "authors": [
+                {
+                    "name": "Edward Z. Yang",
+                    "email": "admin@htmlpurifier.org",
+                    "homepage": "http://ezyang.com"
+                }
+            ],
+            "description": "Standards compliant HTML filter written in PHP",
+            "homepage": "http://htmlpurifier.org/",
+            "keywords": [
+                "html"
+            ],
+            "time": "2013-02-18 00:04:08"
+        },
+        {
+            "name": "michelf/php-markdown",
+            "version": "1.3",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/michelf/php-markdown.git",
+                "reference": "1.3"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/michelf/php-markdown/zipball/1.3",
+                "reference": "1.3",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.0"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-lib": "1.3.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-0": {
+                    "Michelf": ""
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Michel Fortin",
+                    "email": "michel.fortin@michelf.ca",
+                    "homepage": "http://michelf.ca/",
+                    "role": "Developer"
+                },
+                {
+                    "name": "John Gruber",
+                    "homepage": "http://daringfireball.net/"
+                }
+            ],
+            "description": "PHP Markdown",
+            "homepage": "http://michelf.ca/projects/php-markdown/",
+            "keywords": [
+                "markdown"
+            ],
+            "time": "2013-04-11 18:53:11"
+        },
+        {
+            "name": "smarty/smarty",
+            "version": "v3.1.13",
+            "source": {
+                "type": "svn",
+                "url": "http://smarty-php.googlecode.com/svn",
+                "reference": "/tags/v3.1.13/@4699"
+            },
+            "require": {
+                "php": ">=5.2"
+            },
+            "type": "library",
+            "autoload": {
+                "classmap": [
+                    "distribution/libs/Smarty.class.php",
+                    "distribution/libs/SmartyBC.class.php"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "LGPL-3.0"
+            ],
+            "authors": [
+                {
+                    "name": "Monte Ohrt",
+                    "email": "monte@ohrt.com"
+                },
+                {
+                    "name": "Uwe Tews",
+                    "email": "uwe.tews@googlemail.com"
+                },
+                {
+                    "name": "Rodney Rehm",
+                    "email": "rodney.rehm@medialize.de"
+                }
+            ],
+            "description": "Smarty - the compiling PHP template engine",
+            "homepage": "http://www.smarty.net",
+            "keywords": [
+                "templating"
+            ],
+            "time": "2013-01-26 12:03:52"
+        },
+        {
+            "name": "twig/twig",
+            "version": "v1.12.3",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/fabpot/Twig.git",
+                "reference": "v1.12.3"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/fabpot/Twig/zipball/v1.12.3",
+                "reference": "v1.12.3",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.2.4"
+            },
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "1.12-dev"
+                }
+            },
+            "autoload": {
+                "psr-0": {
+                    "Twig_": "lib/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Armin Ronacher",
+                    "email": "armin.ronacher@active-4.com"
+                }
+            ],
+            "description": "Twig, the flexible, fast, and secure template language for PHP",
+            "homepage": "http://twig.sensiolabs.org",
+            "keywords": [
+                "templating"
+            ],
+            "time": "2013-04-08 12:40:11"
+        }
+    ],
+    "packages-dev": [
+
+    ],
+    "aliases": [
+
+    ],
+    "minimum-stability": "stable",
+    "stability-flags": [
+
+    ],
+    "platform": {
+        "php": ">=5.3.0"
+    },
+    "platform-dev": [
+
+    ]
+}
diff --git a/framework/helpers/Markdown.php b/framework/helpers/Markdown.php
new file mode 100644
index 0000000..a8fd0c8
--- /dev/null
+++ b/framework/helpers/Markdown.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @link http://www.yiiframework.com/
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\helpers;
+
+/**
+ * Markdown provides an ability to transform markdown into HTML.
+ *
+ * Basic usage is the following:
+ *
+ * ```php
+ * $my_html = Markdown::process($my_text);
+ * ```
+ *
+ * If you want to configure the parser:
+ *
+ * ```php
+ * $my_html = Markdown::process($my_text, array(
+ *     'fn_id_prefix' => 'footnote_',
+ * ));
+ * ```
+ *
+ * For more details please refer to [PHP Markdown library documentation](http://michelf.ca/projects/php-markdown/).
+ * @author Alexander Makarov <sam@rmcreative.ru>
+ * @since 2.0
+ */
+class Markdown extends base\Markdown
+{
+}
diff --git a/framework/helpers/Purifier.php b/framework/helpers/Purifier.php
new file mode 100644
index 0000000..b659531
--- /dev/null
+++ b/framework/helpers/Purifier.php
@@ -0,0 +1,34 @@
+<?php
+/**
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @link http://www.yiiframework.com/
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\helpers;
+
+/**
+ * Purifier provides an ability to clean up HTML from any harmful code.
+ *
+ * Basic usage is the following:
+ *
+ * ```php
+ * $my_html = Purifier::process($my_text);
+ * ```
+ *
+ * If you want to configure it:
+ *
+ * ```php
+ * $my_html = Purifier::process($my_text, array(
+ *     'Attr.EnableID' => true,
+ * ));
+ * ```
+ *
+ * For more details please refer to HTMLPurifier documentation](http://htmlpurifier.org/).
+ *
+ * @author Alexander Makarov <sam@rmcreative.ru>
+ * @since 2.0
+ */
+class Purifier extends base\Purifier
+{
+}
diff --git a/framework/helpers/base/Markdown.php b/framework/helpers/base/Markdown.php
new file mode 100644
index 0000000..562403f
--- /dev/null
+++ b/framework/helpers/base/Markdown.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @link http://www.yiiframework.com/
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\helpers\base;
+
+\Yii::setAlias('@Michelf', \Yii::getAlias('@yii').'/../vendor/michelf/php-markdown/Michelf');
+use Michelf\MarkdownExtra;
+
+/**
+ * Markdown provides an ability to transform markdown into HTML.
+ *
+ * Basic usage is the following:
+ *
+ * ```php
+ * $my_html = Markdown::process($my_text);
+ * ```
+ *
+ * If you want to configure the parser:
+ *
+ * ```php
+ * $my_html = Markdown::process($my_text, array(
+ *     'fn_id_prefix' => 'footnote_',
+ * ));
+ * ```
+ *
+ * For more details please refer to [PHP Markdown library documentation](http://michelf.ca/projects/php-markdown/).
+ * @author Alexander Makarov <sam@rmcreative.ru>
+ * @since 2.0
+ */
+class Markdown
+{
+	/**
+	 * @var MarkdownExtra
+	 */
+	protected static $markdown;
+
+	public static function process($content, $config = array())
+	{
+		if (static::$markdown===null) {
+			static::$markdown = new MarkdownExtra();
+		}
+		foreach ($config as $name => $value) {
+			static::$markdown->{$name} = $value;
+		}
+		return static::$markdown->transform($content);
+	}
+}
diff --git a/framework/helpers/base/Purifier.php b/framework/helpers/base/Purifier.php
new file mode 100644
index 0000000..cc4ab12
--- /dev/null
+++ b/framework/helpers/base/Purifier.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @link http://www.yiiframework.com/
+ * @license http://www.yiiframework.com/license/
+ */
+namespace yii\helpers\base;
+
+if (!class_exists('HTMLPurifier_Bootstrap', false)) {
+	require_once(\Yii::getAlias('@yii').'/../vendor/ezyang/htmlpurifier/library'.DIRECTORY_SEPARATOR.'HTMLPurifier.auto.php');
+}
+
+/**
+ * Purifier provides an ability to clean up HTML from any harmful code.
+ *
+ * Basic usage is the following:
+ *
+ * ```php
+ * $my_html = Purifier::process($my_text);
+ * ```
+ *
+ * If you want to configure it:
+ *
+ * ```php
+ * $my_html = Purifier::process($my_text, array(
+ *     'Attr.EnableID' => true,
+ * ));
+ * ```
+ *
+ * For more details please refer to HTMLPurifier documentation](http://htmlpurifier.org/).
+ *
+ * @author Alexander Makarov <sam@rmcreative.ru>
+ * @since 2.0
+ */
+class Purifier
+{
+	public static function process($content, $config = null)
+	{
+		$purifier=\HTMLPurifier::instance($config);
+		$purifier->config->set('Cache.SerializerPath', \Yii::$app->getRuntimePath());
+		return $purifier->purify($content);
+	}
+}