diff --git a/phpBB/config/services.yml b/phpBB/config/services.yml
index 51ae5c454d..c6490a21d7 100644
--- a/phpBB/config/services.yml
+++ b/phpBB/config/services.yml
@@ -258,6 +258,15 @@ services:
     php_ini:
         class: phpbb\php\ini
 
+    plupload:
+        class: phpbb\plupload\plupload
+        arguments:
+            - %core.root_path%
+            - @config
+            - @request
+            - @user
+            - @php_ini
+
     request:
         class: phpbb\request\request
 
diff --git a/phpBB/includes/functions_posting.php b/phpBB/includes/functions_posting.php
index ce1238d8e0..1bcef7f1f2 100644
--- a/phpBB/includes/functions_posting.php
+++ b/phpBB/includes/functions_posting.php
@@ -385,8 +385,18 @@ function posting_gen_topic_types($forum_id, $cur_topic_type = POST_NORMAL)
 /**
 * Upload Attachment - filedata is generated here
 * Uses upload class
+*
+* @param string			$form_name		The form name of the file upload input
+* @param int			$forum_id		The id of the forum
+* @param bool			$local			Whether the file is local or not
+* @param string			$local_storage	The path to the local file
+* @param bool			$is_message		Whether it is a PM or not
+* @param \filespec		$local_filedata	A filespec object created for the local file
+* @param \phpbb\plupload\plupload	$plupload		The plupload object if one is being used
+*
+* @return object filespec
 */
-function upload_attachment($form_name, $forum_id, $local = false, $local_storage = '', $is_message = false, $local_filedata = false)
+function upload_attachment($form_name, $forum_id, $local = false, $local_storage = '', $is_message = false, $local_filedata = false, \phpbb\plupload\plupload $plupload = null)
 {
 	global $auth, $user, $config, $db, $cache;
 	global $phpbb_root_path, $phpEx;
@@ -414,7 +424,7 @@ function upload_attachment($form_name, $forum_id, $local = false, $local_storage
 	$extensions = $cache->obtain_attach_extensions((($is_message) ? false : (int) $forum_id));
 	$upload->set_allowed_extensions(array_keys($extensions['_allowed_']));
 
-	$file = ($local) ? $upload->local_upload($local_storage, $local_filedata) : $upload->form_upload($form_name);
+	$file = ($local) ? $upload->local_upload($local_storage, $local_filedata) : $upload->form_upload($form_name, $plupload);
 
 	if ($file->init_error)
 	{
@@ -469,6 +479,11 @@ function upload_attachment($form_name, $forum_id, $local = false, $local_storage
 	{
 		$file->remove();
 
+		if ($plupload && $plupload->is_active())
+		{
+			$plupload->emit_error(104, 'ATTACHED_IMAGE_NOT_IMAGE');
+		}
+
 		// If this error occurs a user tried to exploit an IE Bug by renaming extensions
 		// Since the image category is displaying content inline we need to catch this.
 		trigger_error($user->lang['ATTACHED_IMAGE_NOT_IMAGE']);
diff --git a/phpBB/includes/functions_upload.php b/phpBB/includes/functions_upload.php
index 4181896eca..04d483e14c 100644
--- a/phpBB/includes/functions_upload.php
+++ b/phpBB/includes/functions_upload.php
@@ -43,11 +43,17 @@ class filespec
 
 	var $upload = '';
 
+	/**
+	 * The plupload object
+	 * @var \phpbb\plupload\plupload
+	 */
+	protected $plupload;
+
 	/**
 	* File Class
 	* @access private
 	*/
-	function filespec($upload_ary, $upload_namespace)
+	function filespec($upload_ary, $upload_namespace, \phpbb\plupload\plupload $plupload = null)
 	{
 		if (!isset($upload_ary))
 		{
@@ -80,6 +86,7 @@ class filespec
 
 		$this->local = (isset($upload_ary['local_mode'])) ? true : false;
 		$this->upload = $upload_namespace;
+		$this->plupload = $plupload;
 	}
 
 	/**
@@ -161,12 +168,14 @@ class filespec
 	*/
 	function is_uploaded()
 	{
-		if (!$this->local && !is_uploaded_file($this->filename))
+		$is_plupload = $this->plupload && $this->plupload->is_active();
+
+		if (!$this->local && !$is_plupload && !is_uploaded_file($this->filename))
 		{
 			return false;
 		}
 
-		if ($this->local && !file_exists($this->filename))
+		if (($this->local || $is_plupload) && !file_exists($this->filename))
 		{
 			return false;
 		}
@@ -564,16 +573,28 @@ class fileupload
 	* Upload file from users harddisk
 	*
 	* @param string $form_name Form name assigned to the file input field (if it is an array, the key has to be specified)
+	* @param \phpbb\plupload\plupload $plupload The plupload object
+	*
 	* @return object $file Object "filespec" is returned, all further operations can be done with this object
 	* @access public
 	*/
-	function form_upload($form_name)
+	function form_upload($form_name, \phpbb\plupload\plupload $plupload = null)
 	{
 		global $user, $request;
 
 		$upload = $request->file($form_name);
 		unset($upload['local_mode']);
-		$file = new filespec($upload, $this);
+
+		if ($plupload)
+		{
+			$result = $plupload->handle_upload($form_name);
+			if (is_array($result))
+			{
+				$upload = array_merge($upload, $result);
+			}
+		}
+
+		$file = new filespec($upload, $this, $plupload);
 
 		if ($file->init_error)
 		{
diff --git a/phpBB/includes/message_parser.php b/phpBB/includes/message_parser.php
index 3e348801c7..acd31fd519 100644
--- a/phpBB/includes/message_parser.php
+++ b/phpBB/includes/message_parser.php
@@ -1049,6 +1049,12 @@ class parse_message extends bbcode_firstpass
 
 	var $mode;
 
+	/**
+	* The plupload object used for dealing with attachments
+	* @var \phpbb\plupload\plupload
+	*/
+	protected $plupload;
+
 	/**
 	* Init - give message here or manually
 	*/
@@ -1440,6 +1446,11 @@ class parse_message extends bbcode_firstpass
 
 		if ($preview || $refresh || sizeof($error))
 		{
+			if (isset($this->plupload) && $this->plupload->is_active())
+			{
+				$json_response = new \phpbb\json_response();
+			}
+
 			// Perform actions on temporary attachments
 			if ($delete_file)
 			{
@@ -1484,13 +1495,17 @@ class parse_message extends bbcode_firstpass
 
 					// Reindex Array
 					$this->attachment_data = array_values($this->attachment_data);
+					if (isset($this->plupload) && $this->plupload->is_active())
+					{
+						$json_response->send($this->attachment_data);
+					}
 				}
 			}
 			else if (($add_file || $preview) && $upload_file)
 			{
 				if ($num_attachments < $cfg['max_attachments'] || $auth->acl_gets('m_', 'a_', $forum_id))
 				{
-					$filedata = upload_attachment($form_name, $forum_id, false, '', $is_message);
+					$filedata = upload_attachment($form_name, $forum_id, false, '', $is_message, false, $this->plupload);
 					$error = array_merge($error, $filedata['error']);
 
 					if (!sizeof($error))
@@ -1521,12 +1536,32 @@ class parse_message extends bbcode_firstpass
 						$this->attachment_data = array_merge(array(0 => $new_entry), $this->attachment_data);
 						$this->message = preg_replace('#\[attachment=([0-9]+)\](.*?)\[\/attachment\]#e', "'[attachment='.(\\1 + 1).']\\2[/attachment]'", $this->message);
 						$this->filename_data['filecomment'] = '';
+
+						if (isset($this->plupload) && $this->plupload->is_active())
+						{
+							// Send the client the attachment data to maintain state
+							$json_response->send($this->attachment_data);
+						}
 					}
 				}
 				else
 				{
 					$error[] = $user->lang('TOO_MANY_ATTACHMENTS', (int) $cfg['max_attachments']);
 				}
+
+				if (!empty($error) && isset($this->plupload) && $this->plupload->is_active())
+				{
+					// If this is a plupload (and thus ajax) request, give the
+					// client the first error we have
+					$json_response->send(array(
+						'jsonrpc' => '2.0',
+						'id' => 'id',
+						'error' => array(
+							'code' => 105,
+							'message' => current($error),
+						),
+					));
+				}
 			}
 		}
 
@@ -1687,4 +1722,16 @@ class parse_message extends bbcode_firstpass
 
 		$poll['poll_max_options'] = ($poll['poll_max_options'] < 1) ? 1 : (($poll['poll_max_options'] > $config['max_poll_options']) ? $config['max_poll_options'] : $poll['poll_max_options']);
 	}
+
+	/**
+	* Setter function for passing the plupload object
+	*
+	* @param \phpbb\plupload\plupload $plupload The plupload object
+	*
+	* @return null
+	*/
+	public function set_plupload(\phpbb\plupload\plupload $plupload)
+	{
+		$this->plupload = $plupload;
+	}
 }
diff --git a/phpBB/includes/ucp/ucp_pm_compose.php b/phpBB/includes/ucp/ucp_pm_compose.php
index e0e7a46494..87dfdf902b 100644
--- a/phpBB/includes/ucp/ucp_pm_compose.php
+++ b/phpBB/includes/ucp/ucp_pm_compose.php
@@ -21,9 +21,10 @@ if (!defined('IN_PHPBB'))
 */
 function compose_pm($id, $mode, $action, $user_folders = array())
 {
-	global $template, $db, $auth, $user;
+	global $template, $db, $auth, $user, $cache;
 	global $phpbb_root_path, $phpEx, $config;
 	global $request;
+	global $phpbb_container;
 
 	// Damn php and globals - i know, this is horrible
 	// Needed for handle_message_list_actions()
@@ -385,6 +386,8 @@ function compose_pm($id, $mode, $action, $user_folders = array())
 	}
 
 	$message_parser = new parse_message();
+	$plupload = $phpbb_container->get('plupload');
+	$message_parser->set_plupload($plupload);
 
 	$message_parser->message = ($action == 'reply') ? '' : $message_text;
 	unset($message_text);
@@ -1099,6 +1102,11 @@ function compose_pm($id, $mode, $action, $user_folders = array())
 	// Show attachment box for adding attachments if true
 	$allowed = ($auth->acl_get('u_pm_attach') && $config['allow_pm_attach'] && $form_enctype);
 
+	if ($allowed)
+	{
+		$plupload->configure($cache, $template, $s_action, false);
+	}
+
 	// Attachment entry
 	posting_gen_attachment_entry($attachment_data, $filename_data, $allowed);
 
diff --git a/phpBB/install/install_install.php b/phpBB/install/install_install.php
index c273660d08..1a7e1d1094 100644
--- a/phpBB/install/install_install.php
+++ b/phpBB/install/install_install.php
@@ -1322,6 +1322,10 @@ class install_install extends module
 				SET config_value = '" . md5(mt_rand()) . "'
 				WHERE config_name = 'avatar_salt'",
 
+			'UPDATE ' . $data['table_prefix'] . "config
+				SET config_value = '" . md5(mt_rand()) . "'
+				WHERE config_name = 'plupload_salt'",
+
 			'UPDATE ' . $data['table_prefix'] . "users
 				SET username = '" . $db->sql_escape($data['admin_name']) . "', user_password='" . $db->sql_escape(md5($data['admin_pass1'])) . "', user_ip = '" . $db->sql_escape($user_ip) . "', user_lang = '" . $db->sql_escape($data['default_lang']) . "', user_email='" . $db->sql_escape($data['board_email']) . "', user_dateformat='" . $db->sql_escape($lang['default_dateformat']) . "', user_email_hash = " . $db->sql_escape(phpbb_email_hash($data['board_email'])) . ", username_clean = '" . $db->sql_escape(utf8_clean_string($data['admin_name'])) . "'
 				WHERE username = 'Admin'",
diff --git a/phpBB/install/schemas/schema_data.sql b/phpBB/install/schemas/schema_data.sql
index cd38f86312..094a43c8a0 100644
--- a/phpBB/install/schemas/schema_data.sql
+++ b/phpBB/install/schemas/schema_data.sql
@@ -222,6 +222,7 @@ INSERT INTO phpbb_config (config_name, config_value) VALUES ('new_member_post_li
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('new_member_group_default', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('override_user_style', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('pass_complex', 'PASS_TYPE_ANY');
+INSERT INTO phpbb_config (config_name, config_value) VALUES ('plupload_salt', 'phpbb_plupload');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('pm_edit_time', '0');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('pm_max_boxes', '4');
 INSERT INTO phpbb_config (config_name, config_value) VALUES ('pm_max_msgs', '50');
@@ -284,6 +285,7 @@ INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('num_fi
 INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('num_posts', '1', 1);
 INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('num_topics', '1', 1);
 INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('num_users', '1', 1);
+INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('plupload_last_gc', '0', 1);
 INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('rand_seed', '0', 1);
 INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('rand_seed_last_update', '0', 1);
 INSERT INTO phpbb_config (config_name, config_value, is_dynamic) VALUES ('record_online_date', '0', 1);
diff --git a/phpBB/language/en/plupload.php b/phpBB/language/en/plupload.php
new file mode 100644
index 0000000000..cfdce9810e
--- /dev/null
+++ b/phpBB/language/en/plupload.php
@@ -0,0 +1,65 @@
+<?php
+/**
+*
+* plupload [English]
+*
+* @package language
+* @copyright (c) 2010-2013 Moxiecode Systems AB
+* @copyright (c) 2012 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+/**
+* DO NOT CHANGE
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+if (empty($lang) || !is_array($lang))
+{
+	$lang = array();
+}
+
+// DEVELOPERS PLEASE NOTE
+//
+// All language files should use UTF-8 as their encoding and the files must not contain a BOM.
+//
+// Placeholders can now contain order information, e.g. instead of
+// 'Page %s of %s' you can (and should) write 'Page %1$s of %2$s', this allows
+// translators to re-order the output of data while ensuring it remains correct
+//
+// You do not need this where single placeholders are used, e.g. 'Message %d' is fine
+// equally where a string contains only two placeholders which are used to wrap text
+// in a url you again do not need to specify an order e.g., 'Click %sHERE%s' is fine
+
+$lang = array_merge($lang, array(
+	'PLUPLOAD_ADD_FILES'		=> 'Add files',
+	'PLUPLOAD_ADD_FILES_TO_QUEUE'	=> 'Add files to the upload queue and click the start button.',
+	'PLUPLOAD_DRAG'				=> 'Drag files here.',
+	'PLUPLOAD_ERR_INPUT'		=> 'Failed to open input stream.',
+	'PLUPLOAD_ERR_MOVE_UPLOADED'	=> 'Failed to move uploaded file.',
+	'PLUPLOAD_ERR_OUTPUT'		=> 'Failed to open output stream.',
+	'PLUPLOAD_EXTENSION_ERROR'	=> 'File extension error.',
+	'PLUPLOAD_FILENAME'			=> 'Filename',
+	'PLUPLOAD_FILES_QUEUED'		=> '%d files queued',
+	'PLUPLOAD_GENERIC_ERROR'	=> 'Generic error.',
+	'PLUPLOAD_HTTP_ERROR'		=> 'HTTP error.',
+	'PLUPLOAD_INIT_ERROR'		=> 'Init error.',
+	'PLUPLOAD_IO_ERROR'			=> 'IO error.',
+	'PLUPLOAD_NOT_APPLICABLE'	=> 'N/A',
+	'PLUPLOAD_SECURITY_ERROR'	=> 'Security error.',
+	'PLUPLOAD_SELECT_FILES'		=> 'Select files',
+	'PLUPLOAD_SIZE'				=> 'Size',
+	'PLUPLOAD_SIZE_ERROR'		=> 'File size error.',
+	'PLUPLOAD_STATUS'			=> 'Status',
+	'PLUPLOAD_START_UPLOAD'		=> 'Start upload',
+	'PLUPLOAD_START_CURRENT_UPLOAD'	=> 'Start uploading queue',
+	'PLUPLOAD_STOP_UPLOAD'		=> 'Stop upload',
+	'PLUPLOAD_STOP_CURRENT_UPLOAD'	=> 'Stop current upload',
+	// Note: This string is formatted independently by plupload and so does not
+	// use the same formatting rules as normal phpBB translation strings
+	'PLUPLOAD_UPLOADED'			=> 'Uploaded %d/%d files',
+));
diff --git a/phpBB/phpbb/db/migration/data/v310/alpha1.php b/phpBB/phpbb/db/migration/data/v310/alpha1.php
index 04f195daeb..368c53125e 100644
--- a/phpBB/phpbb/db/migration/data/v310/alpha1.php
+++ b/phpBB/phpbb/db/migration/data/v310/alpha1.php
@@ -27,6 +27,7 @@ class alpha1 extends \phpbb\db\migration\migration
 			'\phpbb\db\migration\data\v310\namespaces',
 			'\phpbb\db\migration\data\v310\notifications_cron',
 			'\phpbb\db\migration\data\v310\notification_options_reconvert',
+			'\phpbb\db\migration\data\v310\plupload',
 			'\phpbb\db\migration\data\v310\signature_module_auth',
 			'\phpbb\db\migration\data\v310\softdelete_mcp_modules',
 			'\phpbb\db\migration\data\v310\teampage',
diff --git a/phpBB/phpbb/db/migration/data/v310/plupload.php b/phpBB/phpbb/db/migration/data/v310/plupload.php
new file mode 100644
index 0000000000..1787c6dafc
--- /dev/null
+++ b/phpBB/phpbb/db/migration/data/v310/plupload.php
@@ -0,0 +1,32 @@
+<?php
+/**
+*
+* @package migration
+* @copyright (c) 2013 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+namespace phpbb\db\migration\data\v310;
+
+class plupload extends \phpbb\db\migration\migration
+{
+	public function effectively_installed()
+	{
+		return isset($this->config['plupload_last_gc']) &&
+			isset($this->config['plupload_salt']);
+	}
+
+	static public function depends_on()
+	{
+		return array('\phpbb\db\migration\data\310\dev');
+	}
+
+	public function update_data()
+	{
+		return array(
+			array('config.add', array('plupload_last_gc', 0)),
+			array('config.add', array('plupload_salt', unique_id())),
+		);
+	}
+}
diff --git a/phpBB/phpbb/plupload/plupload.php b/phpBB/phpbb/plupload/plupload.php
new file mode 100644
index 0000000000..6eb5adf864
--- /dev/null
+++ b/phpBB/phpbb/plupload/plupload.php
@@ -0,0 +1,374 @@
+<?php
+/**
+*
+* @package phpBB3
+* @copyright (c) 2013 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+namespace phpbb\plupload;
+
+/**
+ * @ignore
+ */
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* This class handles all server-side plupload functions
+*
+* @package \phpbb\plupload\plupload
+*/
+class plupload
+{
+	/**
+	* @var string
+	*/
+	protected $phpbb_root_path;
+
+	/**
+	* @var \phpbb\config\config
+	*/
+	protected $config;
+
+	/**
+	* @var \phpbb\request\request_interface
+	*/
+	protected $request;
+
+	/**
+	* @var \phpbb\user
+	*/
+	protected $user;
+
+	/**
+	* @var \phpbb\php\ini
+	*/
+	protected $php_ini;
+
+	/**
+	* Final destination for uploaded files, i.e. the "files" directory.
+	* @var string
+	*/
+	protected $upload_directory;
+
+	/**
+	* Temporary upload directory for plupload uploads.
+	* @var string
+	*/
+	protected $temporary_directory;
+
+	/**
+	* Constructor.
+	*
+	* @param string $phpbb_root_path
+	* @param \phpbb\config\config $config
+	* @param \phpbb\request\request_interface $request
+	* @param \phpbb\user $user
+	* @param \phpbb\php\ini $php_ini
+	*
+	* @return null
+	*/
+	public function __construct($phpbb_root_path, \phpbb\config\config $config, \phpbb\request\request_interface $request, \phpbb\user $user, \phpbb\php\ini $php_ini)
+	{
+		$this->phpbb_root_path = $phpbb_root_path;
+		$this->config = $config;
+		$this->request = $request;
+		$this->user = $user;
+		$this->php_ini = $php_ini;
+
+		$this->upload_directory = $this->phpbb_root_path . $this->config['upload_path'];
+		$this->temporary_directory = $this->upload_directory . '/plupload';
+	}
+
+	/**
+	* Plupload allows for chunking so we must check for that and assemble
+	* the whole file first before performing any checks on it.
+	*
+	* @param string $form_name The name of the file element in the upload form
+	*
+	* @return array|null	null if there are no chunks to piece together
+	*						otherwise array containing the path to the
+	*						pieced-together file and its size
+	*/
+	public function handle_upload($form_name)
+	{
+		$chunks_expected = $this->request->variable('chunks', 0);
+
+		// If chunking is disabled or we are not using plupload, just return
+		// and handle the file as usual
+		if ($chunks_expected < 2)
+		{
+			return;
+		}
+
+		$file_name = $this->request->variable('name', '');
+		$chunk = $this->request->variable('chunk', 0);
+
+		$this->user->add_lang('plupload');
+		$this->prepare_temporary_directory();
+
+		$file_path = $this->temporary_filepath($file_name);
+		$this->integrate_uploaded_file($form_name, $chunk, $file_path);
+
+		// If we are done with all the chunks, strip the .part suffix and then
+		// handle the resulting file as normal, otherwise die and await the
+		// next chunk.
+		if ($chunk == $chunks_expected - 1)
+		{
+			rename("{$file_path}.part", $file_path);
+
+			$file_info = new \Symfony\Component\HttpFoundation\File\File($file_path);
+
+			// Need to modify some of the $_FILES values to reflect the new file
+			return array(
+				'tmp_name' => $file_path,
+				'name' => $this->request->variable('real_filename', ''),
+				'size' => filesize($file_path),
+				'type' => $file_info->getMimeType($file_path),
+			);
+		}
+		else
+		{
+			$json_response = new \phpbb\json_response();
+			$json_response->send(array(
+				'jsonrpc' => '2.0',
+				'id' => 'id',
+				'result' => null,
+			));
+		}
+	}
+
+	/**
+	* Fill in the plupload configuration options in the template
+	*
+	* @param \phpbb\cache\service		$cache
+	* @param \phpbb\template\template	$template
+	* @param string						$s_action The URL to submit the POST data to
+	* @param int						$forum_id The ID of the forum
+	*
+	* @return null
+	*/
+	public function configure(\phpbb\cache\service $cache, \phpbb\template\template $template, $s_action, $forum_id)
+	{
+		$filters = $this->generate_filter_string($cache, $forum_id);
+		$chunk_size = $this->get_chunk_size();
+		$resize = $this->generate_resize_string();
+
+		$template->assign_vars(array(
+			'S_RESIZE'			=> $resize,
+			'S_PLUPLOAD'		=> true,
+			'FILTERS'			=> $filters,
+			'CHUNK_SIZE'		=> $chunk_size,
+			'S_PLUPLOAD_URL'	=> htmlspecialchars_decode($s_action),
+		));
+
+		$this->user->add_lang('plupload');
+	}
+
+	/**
+	* Checks whether the page request was sent by plupload or not
+	*
+	* @return bool
+	*/
+	public function is_active()
+	{
+		return $this->request->header('X-PHPBB-USING-PLUPLOAD', false);
+	}
+
+	/**
+	* Returns whether the current HTTP request is a multipart request.
+	*
+	* @return bool
+	*/
+	public function is_multipart()
+	{
+		$content_type = $this->request->server('CONTENT_TYPE');
+
+		return strpos($content_type, 'multipart') === 0;
+	}
+
+	/**
+	* Sends an error message back to the client via JSON response
+	*
+	* @param int $code		The error code
+	* @param string $msg	The translation string of the message to be sent
+	*
+	* @return null
+	*/
+	public function emit_error($code, $msg)
+	{
+		$json_response = new \phpbb\json_response();
+		$json_response->send(array(
+			'jsonrpc' => '2.0',
+			'id' => 'id',
+			'error' => array(
+				'code' => $code,
+				'message' => $this->user->lang($msg),
+			),
+		));
+	}
+
+	/**
+	* Looks at the list of allowed extensions and generates a string
+	* appropriate for use in configuring plupload with
+	*
+	* @param \phpbb\cache\service $cache
+	* @param string $forum_id The ID of the forum
+	*
+	* @return string
+	*/
+	public function generate_filter_string(\phpbb\cache\service $cache, $forum_id)
+	{
+		$attach_extensions = $cache->obtain_attach_extensions($forum_id);
+		unset($attach_extensions['_allowed_']);
+		$groups = array();
+
+		// Re-arrange the extension array to $groups[$group_name][]
+		foreach ($attach_extensions as $extension => $extension_info)
+		{
+			if (!isset($groups[$extension_info['group_name']]))
+			{
+				$groups[$extension_info['group_name']] = array();
+			}
+
+			$groups[$extension_info['group_name']][] = $extension;
+		}
+
+		$filters = array();
+		foreach ($groups as $group => $extensions)
+		{
+			$filters[] = sprintf(
+				"{title: '%s', extensions: '%s'}",
+				addslashes(ucfirst(strtolower($group))),
+				addslashes(implode(',', $extensions))
+			);
+		}
+
+		return implode(',', $filters);
+	}
+
+	/**
+	* Generates a string that is used to tell plupload to automatically resize
+	* files before uploading them.
+	*
+	* @return string
+	*/
+	public function generate_resize_string()
+	{
+		$resize = '';
+		if ($this->config['img_max_height'] > 0 && $this->config['img_max_width'] > 0)
+		{
+			$resize = sprintf(
+				'resize: {width: %d, height: %d, quality: 100},',
+				(int) $this->config['img_max_height'],
+				(int) $this->config['img_max_width']
+			);
+		}
+
+		return $resize;
+	}
+
+	/**
+	* Checks various php.ini values and the maximum file size to determine
+	* the maximum size chunks a file can be split up into for upload
+	*
+	* @return int
+	*/
+	public function get_chunk_size()
+	{
+		$max = min(
+			$this->php_ini->get_bytes('upload_max_filesize'),
+			$this->php_ini->get_bytes('post_max_size'),
+			max(1, $this->php_ini->get_bytes('memory_limit')),
+			$this->config['max_filesize']
+		);
+
+		// Use half of the maximum possible to leave plenty of room for other
+		// POST data.
+		return floor($max / 2);
+	}
+
+	protected function temporary_filepath($file_name)
+	{
+		// Must preserve the extension for plupload to work.
+		return sprintf(
+			'%s/%s_%s%s',
+			$this->temporary_directory,
+			$this->config['plupload_salt'],
+			md5($file_name),
+			\filespec::get_extension($file_name)
+		);
+	}
+
+	/**
+	* Checks whether the chunk we are about to deal with was actually uploaded
+	* by PHP and actually exists, if not, it generates an error
+	*
+	* @param string $form_name The name of the file in the form data
+	*
+	* @return null
+	*/
+	protected function integrate_uploaded_file($form_name, $chunk, $file_path)
+	{
+		$is_multipart = $this->is_multipart();
+		$upload = $this->request->file($form_name);
+		if ($is_multipart && (!isset($upload['tmp_name']) || !is_uploaded_file($upload['tmp_name'])))
+		{
+			$this->emit_error(103, 'PLUPLOAD_ERR_MOVE_UPLOADED');
+		}
+
+		$tmp_file = $this->temporary_filepath($upload['tmp_name']);
+
+		if (!move_uploaded_file($upload['tmp_name'], $tmp_file))
+		{
+			$this->emit_error(103, 'PLUPLOAD_ERR_MOVE_UPLOADED');
+		}
+
+		$out = fopen("{$file_path}.part", $chunk == 0 ? 'wb' : 'ab');
+		if (!$out)
+		{
+			$this->emit_error(102, 'PLUPLOAD_ERR_OUTPUT');
+		}
+
+		$in = fopen(($is_multipart) ? $tmp_file : 'php://input', 'rb');
+		if (!$in)
+		{
+			$this->emit_error(101, 'PLUPLOAD_ERR_INPUT');
+		}
+
+		while ($buf = fread($in, 4096))
+		{
+			fwrite($out, $buf);
+		}
+
+		fclose($in);
+		fclose($out);
+
+		if ($is_multipart)
+		{
+			unlink($tmp_file);
+		}
+	}
+
+	/**
+	* Creates the temporary directory if it does not already exist.
+	*
+	* @return null
+	*/
+	protected function prepare_temporary_directory()
+	{
+		if (!file_exists($this->temporary_directory))
+		{
+			mkdir($this->temporary_directory);
+
+			copy(
+				$this->upload_directory . '/index.htm',
+				$this->temporary_directory . '/index.htm'
+			);
+		}
+	}
+}
diff --git a/phpBB/posting.php b/phpBB/posting.php
index 1609382551..396b320eac 100644
--- a/phpBB/posting.php
+++ b/phpBB/posting.php
@@ -452,6 +452,8 @@ if ($mode == 'edit')
 $orig_poll_options_size = sizeof($post_data['poll_options']);
 
 $message_parser = new parse_message();
+$plupload = $phpbb_container->get('plupload');
+$message_parser->set_plupload($plupload);
 
 if (isset($post_data['post_text']))
 {
@@ -1551,6 +1553,11 @@ if (($mode == 'post' || ($mode == 'edit' && $post_id == $post_data['topic_first_
 // Show attachment box for adding attachments if true
 $allowed = ($auth->acl_get('f_attach', $forum_id) && $auth->acl_get('u_attach') && $config['allow_attachments'] && $form_enctype);
 
+if ($allowed)
+{
+	$plupload->configure($cache, $template, $s_action, $forum_id);
+}
+
 // Attachment entry
 posting_gen_attachment_entry($attachment_data, $filename_data, $allowed);
 
diff --git a/phpBB/styles/prosilver/template/overall_footer.html b/phpBB/styles/prosilver/template/overall_footer.html
index e26c94f367..b26a4c1610 100644
--- a/phpBB/styles/prosilver/template/overall_footer.html
+++ b/phpBB/styles/prosilver/template/overall_footer.html
@@ -65,6 +65,7 @@
 <!-- EVENT overall_footer_after -->
 
 {$SCRIPTS}
+<!-- IF S_PLUPLOAD --><!-- INCLUDE plupload.html --><!-- ENDIF -->
 
 </body>
 </html>
diff --git a/phpBB/styles/prosilver/template/overall_header.html b/phpBB/styles/prosilver/template/overall_header.html
index 6ca5c86fa4..92baf6ee51 100644
--- a/phpBB/styles/prosilver/template/overall_header.html
+++ b/phpBB/styles/prosilver/template/overall_header.html
@@ -33,6 +33,11 @@
 	<link href="{T_THEME_PATH}/bidi.css?assets_version={T_ASSETS_VERSION}" rel="stylesheet" type="text/css" media="screen, projection" />
 <!-- ENDIF -->
 
+<!-- IF S_PLUPLOAD -->
+	<link href="{T_ASSETS_PATH}/plupload/jquery.plupload.queue/css/jquery.plupload.queue.css?assets_version={T_ASSETS_VERSION}" rel="stylesheet" type="text/css" media="screen, projection" />
+	<link href="{T_THEME_PATH}/plupload.css?assets_version={T_ASSETS_VERSION}" rel="stylesheet" type="text/css" media="screen, projection" />
+<!-- ENDIF -->
+
 <!--[if lte IE 8]>
 	<link href="{T_THEME_PATH}/tweaks.css?assets_version={T_ASSETS_VERSION}" rel="stylesheet" type="text/css" media="screen, projection" />
 <![endif]-->
diff --git a/phpBB/styles/prosilver/template/plupload.html b/phpBB/styles/prosilver/template/plupload.html
new file mode 100644
index 0000000000..564c1b5c36
--- /dev/null
+++ b/phpBB/styles/prosilver/template/plupload.html
@@ -0,0 +1,48 @@
+<script type="text/javascript" src="{T_ASSETS_PATH}/plupload/plupload.js"></script>
+<script type="text/javascript" src="{T_ASSETS_PATH}/plupload/plupload.html5.js"></script>
+<script type="text/javascript" src="{T_ASSETS_PATH}/plupload/jquery.plupload.queue/jquery.plupload.queue.js"></script>
+<script type="text/javascript">
+//<![CDATA[
+phpbb.plupload = {
+	i18n: {
+		'Select files': '{LA_PLUPLOAD_SELECT_FILES}',
+		'Add files to the upload queue and click the start button.': '{LA_PLUPLOAD_ADD_FILES_TO_QUEUE}',
+		'Filename': '{LA_PLUPLOAD_FILENAME}',
+		'Status': '{LA_PLUPLOAD_STATUS}',
+		'Size': '{LA_PLUPLOAD_SIZE}',
+		'Add files': '{LA_PLUPLOAD_ADD_FILES}',
+		'Stop current upload': '{LA_PLUPLOAD_STOP_CURRENT_UPLOAD}',
+		'Start uploading queue': '{LA_PLUPLOAD_START_CURRENT_UPLOAD}',
+		'Uploaded %d/%d files': '{LA_PLUPLOAD_UPLOADED}',
+		'N/A': '{LA_PLUPLOAD_NOT_APPLICABLE}',
+		'Drag files here.': '{LA_PLUPLOAD_DRAG}',
+		'File extension error.': '{LA_PLUPLOAD_EXTENSION_ERROR}',
+		'File size error.': '{LA_PLUPLOAD_SIZE_ERROR}',
+		'Init error.': '{LA_PLUPLOAD_INIT_ERROR}',
+		'HTTP Error.': '{LA_PLUPLOAD_HTTP_ERROR}',
+		'Security error.': '{LA_PLUPLOAD_SECURITY_ERROR}',
+		'Generic error.': '{LA_PLUPLOAD_GENERIC_ERROR}',
+		'IO error.': '{LA_PLUPLOAD_IO_ERROR}',
+		'Stop Upload': '{LA_PLUPLOAD_STOP_UPLOAD}',
+		'Start upload': '{LA_PLUPLOAD_START_UPLOAD}',
+		'%d files queued': '{LA_PLUPLOAD_FILES_QUEUED}'
+	},
+	config: {
+		runtimes: 'html5',
+		url: '{S_PLUPLOAD_URL}',
+		max_file_size: '{FILESIZE}b',
+		chunk_size: '{CHUNK_SIZE}b',
+		unique_names: true,
+		filters: [{FILTERS}],
+		{S_RESIZE}
+		headers: {'X-PHPBB-USING-PLUPLOAD': '1'},
+		file_data_name: 'fileupload',
+		multipart_params: {'add_file': '{LA_ADD_FILE}'},
+		img_path: '{T_ASSETS_PATH}/plupload/jquery.plupload.queue/img',
+		element_hook: '#attach-panel .inner',
+		form_hook: '#postform'
+	}
+};
+//]]>
+</script>
+<script type="text/javascript" src="{T_ASSETS_PATH}/javascript/plupload.js"></script>
diff --git a/phpBB/styles/prosilver/theme/plupload.css b/phpBB/styles/prosilver/theme/plupload.css
new file mode 100644
index 0000000000..16c26822b5
--- /dev/null
+++ b/phpBB/styles/prosilver/theme/plupload.css
@@ -0,0 +1,11 @@
+.plupload_filelist li.can_delete:hover {
+	cursor: pointer;
+}
+
+.plupload_filelist li.can_delete:hover a {
+	background: url('../../../assets/plupload/jquery.plupload.queue/img/delete.gif');
+}
+
+.plupload_filelist li a.working {
+	background: url('../../../assets/plupload/jquery.plupload.queue/img/throbber.gif');
+}
diff --git a/tests/functional/fileupload_form_test.php b/tests/functional/fileupload_form_test.php
index 998c402fa3..ad01d7b2df 100644
--- a/tests/functional/fileupload_form_test.php
+++ b/tests/functional/fileupload_form_test.php
@@ -22,6 +22,25 @@ class phpbb_functional_fileupload_form_test extends phpbb_functional_test_case
 		$this->login();
 	}
 
+	public function tearDown()
+	{
+		$iterator = new DirectoryIterator(__DIR__ . '/../../phpBB/files/');
+		foreach ($iterator as $fileinfo)
+		{
+			if (
+				$fileinfo->isDot()
+				|| $fileinfo->isDir()
+				|| $fileinfo->getFilename() === 'index.htm'
+				|| $fileinfo->getFilename() === '.htaccess'
+			)
+			{
+				continue;
+			}
+
+			unlink($fileinfo->getPathname());
+		}
+	}
+
 	private function upload_file($filename, $mimetype)
 	{
 		$file = array(
diff --git a/tests/functional/plupload_test.php b/tests/functional/plupload_test.php
new file mode 100644
index 0000000000..6dd9224839
--- /dev/null
+++ b/tests/functional/plupload_test.php
@@ -0,0 +1,149 @@
+<?php
+/**
+ *
+ * @package testing
+ * @copyright (c) 2012 phpBB Group
+ * @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+ *
+ */
+
+/**
+ * @group functional
+ */
+class phpbb_functional_plupload_test extends phpbb_functional_test_case
+{
+	const CHUNKS = 4;
+	private $path;
+
+	protected function set_extension_group_permission($val)
+	{
+		$db = $this->get_db();
+		$query = "
+			UPDATE phpbb_extension_groups
+			SET allow_in_pm = '$val'
+			WHERE group_name = 'IMAGES'
+		";
+		$db->sql_query($query);
+	}
+
+	public function setUp()
+	{
+		parent::setUp();
+		$this->set_extension_group_permission(1);
+		$this->path = __DIR__ . '/fixtures/files/';
+		$this->add_lang('posting');
+		$this->login();
+	}
+
+	public function tearDown()
+	{
+		$this->set_extension_group_permission(0);
+		$iterator = new DirectoryIterator(__DIR__ . '/../../phpBB/files/');
+		foreach ($iterator as $fileinfo)
+		{
+			if (
+				$fileinfo->isDot()
+				|| $fileinfo->isDir()
+				|| $fileinfo->getFilename() === 'index.htm'
+				|| $fileinfo->getFilename() === '.htaccess'
+			)
+			{
+				continue;
+			}
+
+			unlink($fileinfo->getPathname());
+		}
+	}
+
+	public function get_urls()
+	{
+		return array(
+			array('posting.php?mode=reply&f=2&t=1'),
+			array('ucp.php?i=pm&mode=compose'),
+		);
+	}
+
+	/**
+	 * @dataProvider get_urls
+	 */
+	public function test_chunked_upload($url)
+	{
+		$chunk_size = ceil(filesize($this->path . 'valid.jpg') / self::CHUNKS);
+		$handle = fopen($this->path . 'valid.jpg', 'rb');
+
+		for ($i = 0; $i < self::CHUNKS; $i++)
+		{
+			$chunk = fread($handle, $chunk_size);
+			file_put_contents($this-> path . 'chunk', $chunk);
+
+			$file = array(
+				'tmp_name' => $this->path . 'chunk',
+				'name' => 'blob',
+				'type' => 'application/octet-stream',
+				'size' => strlen($chunk),
+				'error' => UPLOAD_ERR_OK,
+			);
+
+			self::$client->setServerParameter('HTTP_X_PHPBB_USING_PLUPLOAD', '1');
+
+			$crawler = self::$client->request(
+				'POST',
+				$url . '&sid=' . $this->sid,
+				array(
+					'chunk' => $i,
+					'chunks' => self::CHUNKS,
+					'name' => md5('valid') . '.jpg',
+					'real_filename' => 'valid.jpg',
+					'add_file' => $this->lang('ADD_FILE'),
+				),
+				array('fileupload' => $file),
+				array('X-PHPBB-USING-PLUPLOAD' => '1')
+			);
+
+			if ($i < self::CHUNKS - 1)
+			{
+				$this->assertContains('{"jsonrpc":"2.0","id":"id","result":null}', self::$client->getResponse()->getContent());
+			}
+			else
+			{
+				$response = json_decode(self::$client->getResponse()->getContent(), true);
+				$this->assertEquals('valid.jpg', $response[0]['real_filename']);
+			}
+
+			unlink($this->path . 'chunk');
+		}
+
+		fclose($handle);
+	}
+
+	/**
+	 * @dataProvider get_urls
+	 */
+	public function test_normal_upload($url)
+	{
+		$file = array(
+			'tmp_name' => $this->path . 'valid.jpg',
+			'name' => 'valid.jpg',
+			'type' => 'image/jpeg',
+			'size' => filesize($this->path . 'valid.jpg'),
+			'error' => UPLOAD_ERR_OK,
+		);
+
+		$crawler = self::$client->request(
+			'POST',
+			$url . '&sid=' . $this->sid,
+			array(
+				'chunk' => '0',
+				'chunks' => '1',
+				'name' => md5('valid') . '.jpg',
+				'real_filename' => 'valid.jpg',
+				'add_file' => $this->lang('ADD_FILE'),
+			),
+			array('fileupload' => $file),
+			array('X-PHPBB-USING-PLUPLOAD' => '1')
+		);
+
+		$response = json_decode(self::$client->getResponse()->getContent(), true);
+		$this->assertEquals('valid.jpg', $response[0]['real_filename']);
+	}
+}