diff --git a/apps/files_versions/appinfo/app.php b/apps/files_versions/appinfo/app.php
new file mode 100644
index 00000000000..6e7a803252e
--- /dev/null
+++ b/apps/files_versions/appinfo/app.php
@@ -0,0 +1,19 @@
+<?php
+
+require_once('apps/files_versions/versions.php');
+
+// Add an entry in the app list
+OC_App::register( array(
+  'order' => 10,
+  'id' => 'files_versions',
+  'name' => 'Versioning' ));
+
+OC_APP::registerAdmin('files_versions', 'settings');
+
+// Listen to write signals
+OC_Hook::connect(OC_Filesystem::CLASSNAME, OC_Filesystem::signal_post_write, "OCA_Versions\Storage", "write_hook");
+
+
+
+
+?>
diff --git a/apps/files_versions/appinfo/info.xml b/apps/files_versions/appinfo/info.xml
new file mode 100644
index 00000000000..9936a2ad8b2
--- /dev/null
+++ b/apps/files_versions/appinfo/info.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<info>
+    <id>files_versions</id>
+    <name>Versions</name>
+    <licence>AGPL</licence>
+    <author>Frank Karlitschek</author>
+    <require>3</require>
+    <description>Versioning of files</description>
+	<types>
+		<filesystem/>
+	</types>
+</info>
diff --git a/apps/files_versions/appinfo/version b/apps/files_versions/appinfo/version
new file mode 100644
index 00000000000..afaf360d37f
--- /dev/null
+++ b/apps/files_versions/appinfo/version
@@ -0,0 +1 @@
+1.0.0
\ No newline at end of file
diff --git a/apps/files_versions/css/versions.css b/apps/files_versions/css/versions.css
new file mode 100644
index 00000000000..139597f9cb0
--- /dev/null
+++ b/apps/files_versions/css/versions.css
@@ -0,0 +1,2 @@
+
+
diff --git a/apps/files_versions/history.php b/apps/files_versions/history.php
new file mode 100644
index 00000000000..6c7626ca4ed
--- /dev/null
+++ b/apps/files_versions/history.php
@@ -0,0 +1,60 @@
+<?php
+
+/**
+ * ownCloud - History page of the Versions App
+ *
+ * @author Frank Karlitschek
+ * @copyright 2011 Frank Karlitschek karlitschek@kde.org
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either 
+ * version 3 of the License, or any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *  
+ * You should have received a copy of the GNU Lesser General Public 
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+require_once('../../lib/base.php');
+
+OC_Util::checkLoggedIn();
+
+if (isset($_GET['path'])) {
+
+	$path = $_GET['path'];
+	$path = strip_tags($path);
+
+	// roll back to old version if button clicked
+        if(isset($_GET['revert'])) {
+        	\OCA_Versions\Storage::rollback($path,$_GET['revert']);
+	}
+
+	// show the history only if there is something to show
+        if(OCA_Versions\Storage::isversioned($path)) {
+
+		$count=5; //show the newest revisions
+	        $versions=OCA_Versions\Storage::getversions($path,$count);
+
+		$tmpl = new OC_Template('files_versions', 'history', 'user');
+		$tmpl->assign('path', $path);
+		$tmpl->assign('versions', array_reverse($versions));
+		$tmpl->printPage();
+	}else{
+		$tmpl = new OC_Template('files_versions', 'history', 'user');
+		$tmpl->assign('path', $path);
+		$tmpl->assign('message', 'No old versions available');
+		$tmpl->printPage();
+	}
+}else{
+	$tmpl = new OC_Template('files_versions', 'history', 'user');
+	$tmpl->assign('message', 'No path specified');
+	$tmpl->printPage();
+}
+
+
+?>
diff --git a/apps/files_versions/js/versions.js b/apps/files_versions/js/versions.js
new file mode 100644
index 00000000000..139597f9cb0
--- /dev/null
+++ b/apps/files_versions/js/versions.js
@@ -0,0 +1,2 @@
+
+
diff --git a/apps/files_versions/settings.php b/apps/files_versions/settings.php
new file mode 100644
index 00000000000..eb154d3edd3
--- /dev/null
+++ b/apps/files_versions/settings.php
@@ -0,0 +1,10 @@
+<?php
+
+OC_Util::checkAdminUser();
+
+OC_Util::addScript( 'files_versions', 'versions' );
+
+$tmpl = new OC_Template( 'files_versions', 'settings');
+
+return $tmpl->fetchPage();
+?>
diff --git a/apps/files_versions/templates/history.php b/apps/files_versions/templates/history.php
new file mode 100644
index 00000000000..1b3de9ce77c
--- /dev/null
+++ b/apps/files_versions/templates/history.php
@@ -0,0 +1,18 @@
+<?php
+	if(isset($_['message'])){
+
+
+	        if(isset($_['path'])) echo('<strong>File: '.$_['path']).'</strong><br>';
+	        echo('<strong>'.$_['message']).'</strong><br>';
+
+	}else{
+
+	        echo('<strong>Versions of '.$_['path']).'</strong><br>';
+	        echo('<p><em>You can click on the revert button to revert to the specific verson.</em></p><br />');
+	        foreach ($_['versions'] as $v){
+			echo(' '.OC_Util::formatDate($v).' <a href="history.php?path='.urlencode($_['path']).'&revert='.$v.'" class="button">revert</a><br /><br />');
+		}
+
+	}
+
+?>
diff --git a/apps/files_versions/templates/settings.php b/apps/files_versions/templates/settings.php
new file mode 100644
index 00000000000..8c8def94429
--- /dev/null
+++ b/apps/files_versions/templates/settings.php
@@ -0,0 +1,7 @@
+<form id="external">
+	<fieldset class="personalblock">
+		<strong>Versions</strong><br />
+
+		Configuration goes here...
+	</fieldset>
+</form>
diff --git a/apps/files_versions/versions.php b/apps/files_versions/versions.php
new file mode 100644
index 00000000000..156a4f59c73
--- /dev/null
+++ b/apps/files_versions/versions.php
@@ -0,0 +1,216 @@
+<?php
+/**
+ * Copyright (c) 2012 Frank Karlitschek <frank@owncloud.org>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+/**
+ * Versions
+ *
+ * A class to handle the versioning of files.
+ */
+
+namespace OCA_Versions;
+
+class Storage {
+
+
+	// config.php configuration:
+	//   - files_versions
+	//   - files_versionsfolder
+	//   - files_versionsblacklist
+	//   - files_versionsmaxfilesize
+	//   - files_versionsinterval 
+	//   - files_versionmaxversions 
+	//
+	// todo:
+	//   - port to oc_filesystem to enable network transparency
+	//   - check if it works well together with encryption
+	//   - do configuration web interface
+	//   - implement expire all function. And find a place to call it ;-)
+	//   - add transparent compression. first test if it´s worth it.
+
+	const DEFAULTENABLED=true; 
+	const DEFAULTFOLDER='versions'; 
+	const DEFAULTBLACKLIST='avi mp3 mpg mp4'; 
+	const DEFAULTMAXFILESIZE=1048576; // 10MB 
+	const DEFAULTMININTERVAL=300; // 5 min
+	const DEFAULTMAXVERSIONS=50; 
+
+	/**
+	 * init the versioning and create the versions folder.
+	 */
+	public static function init() {
+		if(\OC_Config::getValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+			// create versions folder
+			$foldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/'.\OC_Config::getValue('files_versionsfolder', Storage::DEFAULTFOLDER);
+			if(!is_dir($foldername)){
+				mkdir($foldername);
+			}
+		}
+	}
+
+
+	/**
+	 * listen to write event.
+	 */
+	public static function write_hook($params) {
+		if(\OC_Config::getValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+			$path = $params[\OC_Filesystem::signal_param_path];
+			if($path<>'') Storage::store($path);
+		}
+	}
+
+
+
+	/**
+	 * store a new version of a file.
+	 */
+	public static function store($filename) {
+		if(\OC_Config::getValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+			$versionsfoldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/'.\OC_Config::getValue('files_versionsfolder', Storage::DEFAULTFOLDER);
+			$filesfoldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/files';
+			Storage::init();
+
+			// check if filename is a directory
+			if(is_dir($filesfoldername.$filename)){
+				return false;
+			}
+
+			// check filetype blacklist
+			$blacklist=explode(' ',\OC_Config::getValue('files_versionsblacklist', Storage::DEFAULTBLACKLIST));
+			foreach($blacklist as $bl) {
+				$parts=explode('.', $filename);
+				$ext=end($parts);
+				if(strtolower($ext)==$bl) {
+					return false;
+				}
+			}
+			
+			// check filesize
+			if(filesize($filesfoldername.$filename)>\OC_Config::getValue('files_versionsmaxfilesize', Storage::DEFAULTMAXFILESIZE)){
+				return false;
+			}
+
+
+			// check mininterval
+			$matches=glob($versionsfoldername.$filename.'.v*');
+			sort($matches);
+			$parts=explode('.v',end($matches));
+			if((end($parts)+Storage::DEFAULTMININTERVAL)>time()){
+				return false;
+			}
+			
+
+			// create all parent folders
+			$info=pathinfo($filename);	
+			@mkdir($versionsfoldername.$info['dirname'],0700,true);	
+
+
+			// store a new version of a file
+			copy($filesfoldername.$filename,$versionsfoldername.$filename.'.v'.time());
+        
+			// expire old revisions
+			Storage::expire($filename);
+		}
+	}
+
+
+	/**
+	 * rollback to an old version of a file.
+	 */
+	public static function rollback($filename,$revision) {
+		if(\OC_Config::getValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+			$versionsfoldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/'.\OC_Config::getValue('files_versionsfolder', Storage::DEFAULTFOLDER);
+			$filesfoldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/files';
+			// rollback
+			@copy($versionsfoldername.$filename.'.v'.$revision,$filesfoldername.$filename);
+		}
+	}
+
+	/**
+	 * check if old versions of a file exist.
+	 */
+	public static function isversioned($filename) {
+		if(\OC_Config::getValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+			$versionsfoldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/'.\OC_Config::getValue('files_versionsfolder', Storage::DEFAULTFOLDER);
+
+			// check for old versions
+			$matches=glob($versionsfoldername.$filename.'.v*');
+			if(count($matches)>1){
+				return true;
+			}else{
+				return false;
+			}
+		}else{
+			return(false);
+		}
+	}
+
+
+        
+        /**
+         * get a list of old versions of a file.
+         */
+        public static function getversions($filename,$count=0) {
+                if(\OC_Config::getValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+			$versionsfoldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/'.\OC_Config::getValue('files_versionsfolder', Storage::DEFAULTFOLDER);
+			$versions=array();         
+ 
+	              // fetch for old versions
+			$matches=glob($versionsfoldername.$filename.'.v*');
+			sort($matches);
+			foreach($matches as $ma) {
+				$parts=explode('.v',$ma);
+				$versions[]=(end($parts));
+			}
+			
+			// only show the newest commits
+			if($count<>0 and (count($versions)>$count)) {
+				$versions=array_slice($versions,count($versions)-$count);
+			}
+	
+			return($versions);
+
+
+                }else{
+                        return(array());
+                }
+        }	
+
+
+        
+        /**
+         * expire old versions of a file.
+         */
+        public static function expire($filename) {
+                if(\OC_Config::getValue('files_versions', Storage::DEFAULTENABLED)=='true') {
+
+			$versionsfoldername=\OC_Config::getValue('datadirectory').'/'. \OC_User::getUser() .'/'.\OC_Config::getValue('files_versionsfolder', Storage::DEFAULTFOLDER);
+
+			// check for old versions
+			$matches=glob($versionsfoldername.$filename.'.v*');
+			if(count($matches)>\OC_Config::getValue('files_versionmaxversions', Storage::DEFAULTMAXVERSIONS)){
+				$numbertodelete=count($matches-\OC_Config::getValue('files_versionmaxversions', Storage::DEFAULTMAXVERSIONS));
+
+				// delete old versions of a file
+				$deleteitems=array_slice($matches,0,$numbertodelete);
+				foreach($deleteitems as $de){
+					unlink($versionsfoldername.$filename.'.v'.$de);
+				}
+			}
+                }
+        }
+
+        /**
+         * expire all old versions.
+         */
+        public static function expireall($filename) {
+		// todo this should go through all the versions directories and delete all the not needed files and not needed directories.
+		// useful to be included in a cleanup cronjob.
+        }
+
+
+}