diff --git a/plugins/libkolab/lib/kolab_format.php b/plugins/libkolab/lib/kolab_format.php
index 23246d32..bedee440 100644
--- a/plugins/libkolab/lib/kolab_format.php
+++ b/plugins/libkolab/lib/kolab_format.php
@@ -31,38 +31,59 @@ abstract class kolab_format
 
     public /*abstract*/ $CTYPE;
 
+    protected /*abstract*/ $objclass;
     protected /*abstract*/ $read_func;
     protected /*abstract*/ $write_func;
 
     protected $obj;
     protected $data;
     protected $xmldata;
+    protected $xmlobject;
     protected $loaded = false;
+    protected $version = 3.0;
 
-    const VERSION = '3.0';
     const KTYPE_PREFIX = 'application/x-vnd.kolab.';
+    const PRODUCT_ID = 'Roundcube-libkolab-0.9';
 
     /**
-     * Factory method to instantiate a kolab_format object of the given type
+     * Factory method to instantiate a kolab_format object of the given type and version
      *
      * @param string Object type to instantiate
      * @param string Cached xml data to initialize with
+     * @param float  Format version
      * @return object kolab_format
      */
-    public static function factory($type, $xmldata = null)
+    public static function factory($type, $xmldata = null, $version = 3.0)
     {
         if (!isset(self::$timezone))
             self::$timezone = new DateTimeZone('UTC');
 
+        if (!self::supports($version))
+            return PEAR::raiseError("No support for Kolab format version " . $version);
+
         $type = preg_replace('/configuration\.[a-z.]+$/', 'configuration', $type);
         $suffix = preg_replace('/[^a-z]+/', '', $type);
         $classname = 'kolab_format_' . $suffix;
         if (class_exists($classname))
-            return new $classname($xmldata);
+            return new $classname($xmldata, $version);
 
         return PEAR::raiseError("Failed to load Kolab Format wrapper for type " . $type);
     }
 
+    /**
+     * Determine support for the given format version
+     *
+     * @param float Format version to check
+     * @return boolean True if supported, False otherwise
+     */
+    public static function supports($version)
+    {
+        if ($version == 2.0)
+            return class_exists('kolabobject');
+        // default is version 3
+        return class_exists('kolabformat');
+    }
+
     /**
      * Convert the given date/time value into a cDateTime object
      *
@@ -184,6 +205,23 @@ abstract class kolab_format
         return preg_replace('/dictionary.[a-z.]+$/', 'dictionary', substr($x_kolab_type, strlen(self::KTYPE_PREFIX)));
     }
 
+
+    /**
+     * Default constructor of all kolab_format_* objects
+     */
+    public function __construct($xmldata = null, $version = null)
+    {
+        $this->obj = new $this->objclass;
+        $this->xmldata = $xmldata;
+
+        if ($version)
+            $this->version = $version;
+
+        // use libkolab module if available
+        if (class_exists('kolabobject'))
+            $this->xmlobject = new XMLObject();
+    }
+
     /**
      * Check for format errors after calling kolabformat::write*()
      *
@@ -245,6 +283,39 @@ abstract class kolab_format
         }
     }
 
+    /**
+     * Get constant value for libkolab's version parameter
+     *
+     * @param float Version value to convert
+     * @return int Constant value of either kolabobject::KolabV2 or kolabobject::KolabV3 or false if kolabobject module isn't available
+     */
+    protected function libversion($v = null)
+    {
+        if (class_exists('kolabobject')) {
+            $version = $v ?: $this->version;
+            if ($version <= 2.0)
+                return kolabobject::KolabV2;
+            else
+                return kolabobject::KolabV3;
+        }
+
+        return false;
+    }
+
+    /**
+     * Determine the correct libkolab(xml) wrapper function for the given call
+     * depending on the available PHP modules
+     */
+    protected function libfunc($func)
+    {
+        if (is_array($func) || strpos($func, '::'))
+            return $func;
+        else if (class_exists('kolabobject'))
+            return array($this->xmlobject, $func);
+        else
+            return 'kolabformat::' . $func;
+    }
+
     /**
      * Direct getter for object properties
      */
@@ -257,22 +328,29 @@ abstract class kolab_format
      * Load Kolab object data from the given XML block
      *
      * @param string XML data
+     * @return boolean True on success, False on failure
      */
     public function load($xml)
     {
-        $this->obj = call_user_func($this->read_func, $xml, false);
+        $r = call_user_func($this->libfunc($this->read_func), $xml, $this->libversion());
+        if (is_resource($r))
+            $this->obj = new $this->objclass($r);
+        else if (is_a($r, $this->objclass))
+            $this->obj = $r;
+
         $this->loaded = !$this->format_errors();
     }
 
     /**
      * Write object data to XML format
      *
+     * @param float Format version to write
      * @return string XML data
      */
-    public function write()
+    public function write($version = null)
     {
         $this->init();
-        $this->xmldata = call_user_func($this->write_func, $this->obj);
+        $this->xmldata = call_user_func($this->libfunc($this->write_func), $this->obj, $this->libversion($version), self::PRODUCT_ID);
 
         if (!$this->format_errors())
             $this->update_uid();
diff --git a/plugins/libkolab/lib/kolab_format_configuration.php b/plugins/libkolab/lib/kolab_format_configuration.php
index 974fc453..1bb919d3 100644
--- a/plugins/libkolab/lib/kolab_format_configuration.php
+++ b/plugins/libkolab/lib/kolab_format_configuration.php
@@ -26,6 +26,7 @@ class kolab_format_configuration extends kolab_format
 {
     public $CTYPE = 'application/x-vnd.kolab.configuration';
 
+    protected $objclass = 'Configuration';
     protected $read_func = 'kolabformat::readConfiguration';
     protected $write_func = 'kolabformat::writeConfiguration';
 
@@ -35,12 +36,6 @@ class kolab_format_configuration extends kolab_format
     );
 
 
-    function __construct($xmldata = null)
-    {
-        $this->obj = new Configuration;
-        $this->xmldata = $xmldata;
-    }
-
     /**
      * Set properties to the kolabformat object
      *
diff --git a/plugins/libkolab/lib/kolab_format_contact.php b/plugins/libkolab/lib/kolab_format_contact.php
index ffef059d..bae5fa33 100644
--- a/plugins/libkolab/lib/kolab_format_contact.php
+++ b/plugins/libkolab/lib/kolab_format_contact.php
@@ -26,8 +26,9 @@ class kolab_format_contact extends kolab_format
 {
     public $CTYPE = 'application/vcard+xml';
 
-    protected $read_func = 'kolabformat::readContact';
-    protected $write_func = 'kolabformat::writeContact';
+    protected $objclass = 'Contact';
+    protected $read_func = 'readContact';
+    protected $write_func = 'writeContact';
 
     public static $fulltext_cols = array('name', 'firstname', 'surname', 'middlename', 'email');
 
@@ -106,10 +107,9 @@ class kolab_format_contact extends kolab_format
     /**
      * Default constructor
      */
-    function __construct($xmldata = null)
+    function __construct($xmldata = null, $version = 3.0)
     {
-        $this->obj = new Contact;
-        $this->xmldata = $xmldata;
+        parent::__construct($xmldata, $version);
 
         // complete phone types
         $this->phonetypes['homefax'] |= Telephone::Home;
diff --git a/plugins/libkolab/lib/kolab_format_distributionlist.php b/plugins/libkolab/lib/kolab_format_distributionlist.php
index fcb94c14..6def48fd 100644
--- a/plugins/libkolab/lib/kolab_format_distributionlist.php
+++ b/plugins/libkolab/lib/kolab_format_distributionlist.php
@@ -26,16 +26,11 @@ class kolab_format_distributionlist extends kolab_format
 {
     public $CTYPE = 'application/vcard+xml';
 
-    protected $read_func = 'kolabformat::readDistlist';
-    protected $write_func = 'kolabformat::writeDistlist';
+    protected $objclass = 'DistList';
+    protected $read_func = 'readDistlist';
+    protected $write_func = 'writeDistlist';
 
 
-    function __construct($xmldata = null)
-    {
-        $this->obj = new DistList;
-        $this->xmldata = $xmldata;
-    }
-
     /**
      * Set properties to the kolabformat object
      *
diff --git a/plugins/libkolab/lib/kolab_format_event.php b/plugins/libkolab/lib/kolab_format_event.php
index 4e790f2b..b2cb87b9 100644
--- a/plugins/libkolab/lib/kolab_format_event.php
+++ b/plugins/libkolab/lib/kolab_format_event.php
@@ -24,8 +24,9 @@
 
 class kolab_format_event extends kolab_format_xcal
 {
-    protected $read_func = 'kolabformat::readEvent';
-    protected $write_func = 'kolabformat::writeEvent';
+    protected $objclass = 'Event';
+    protected $read_func = 'readEvent';
+    protected $write_func = 'writeEvent';
 
     private $kolab2_rolemap = array(
         'required' => 'REQ-PARTICIPANT',
@@ -43,24 +44,15 @@ class kolab_format_event extends kolab_format_xcal
 
 
     /**
-     * Default constructor
+     * Clones into an instance of libcalendaring's extended EventCal class
+     *
+     * @return mixed EventCal object or false on failure
      */
-    function __construct($xmldata = null)
+    public function to_libcal()
     {
-        $this->obj = new Event;
-        $this->xmldata = $xmldata;
+        return class_exists('kolabcalendaring') ? new EventCal($this->obj) : false;
     }
 
-	/**
-	 * Clones into an instance of libcalendaring's extended EventCal class
-	 *
-	 * @return mixed EventCal object or false on failure
-	 */
-	public function to_libcal()
-	{
-		return class_exists('kolabcalendaring') ? new EventCal($this->obj) : false;
-	}
-
     /**
      * Set event properties to the kolabformat object
      *
diff --git a/plugins/libkolab/lib/kolab_format_journal.php b/plugins/libkolab/lib/kolab_format_journal.php
index 5869af09..0e1b4743 100644
--- a/plugins/libkolab/lib/kolab_format_journal.php
+++ b/plugins/libkolab/lib/kolab_format_journal.php
@@ -26,16 +26,11 @@ class kolab_format_journal extends kolab_format
 {
     public $CTYPE = 'application/calendar+xml';
 
-    protected $read_func = 'kolabformat::readJournal';
-    protected $write_func = 'kolabformat::writeJournal';
+    protected $objclass = 'Journal';
+    protected $read_func = 'readJournal';
+    protected $write_func = 'writeJournal';
 
 
-    function __construct($xmldata = null)
-    {
-        $this->obj = new Journal;
-        $this->xmldata = $xmldata;
-    }
-
     /**
      * Set properties to the kolabformat object
      *
diff --git a/plugins/libkolab/lib/kolab_format_note.php b/plugins/libkolab/lib/kolab_format_note.php
index 1c88a8bb..482a3e8f 100644
--- a/plugins/libkolab/lib/kolab_format_note.php
+++ b/plugins/libkolab/lib/kolab_format_note.php
@@ -26,16 +26,11 @@ class kolab_format_note extends kolab_format
 {
     public $CTYPE = 'application/x-vnd.kolab.note';
 
-    protected $read_func = 'kolabformat::readNote';
-    protected $write_func = 'kolabformat::writeNote';
+    protected $objclass = 'Note';
+    protected $read_func = 'readNote';
+    protected $write_func = 'writeNote';
 
 
-    function __construct($xmldata = null)
-    {
-        $this->obj = new Note;
-        $this->xmldata = $xmldata;
-    }
-
     /**
      * Set properties to the kolabformat object
      *
diff --git a/plugins/libkolab/lib/kolab_format_task.php b/plugins/libkolab/lib/kolab_format_task.php
index 2a7a629f..425f5e06 100644
--- a/plugins/libkolab/lib/kolab_format_task.php
+++ b/plugins/libkolab/lib/kolab_format_task.php
@@ -24,16 +24,11 @@
 
 class kolab_format_task extends kolab_format_xcal
 {
-    protected $read_func = 'kolabformat::readTodo';
-    protected $write_func = 'kolabformat::writeTodo';
+    protected $objclass = 'Todo';
+    protected $read_func = 'readTodo';
+    protected $write_func = 'writeTodo';
 
 
-    function __construct($xmldata = null)
-    {
-        $this->obj = new Todo;
-        $this->xmldata = $xmldata;
-    }
-
     /**
      * Set properties to the kolabformat object
      *
diff --git a/plugins/libkolab/lib/kolab_storage.php b/plugins/libkolab/lib/kolab_storage.php
index 12419340..ac7de34b 100644
--- a/plugins/libkolab/lib/kolab_storage.php
+++ b/plugins/libkolab/lib/kolab_storage.php
@@ -31,6 +31,7 @@ class kolab_storage
     const SERVERSIDE_SUBSCRIPTION = 0;
     const CLIENTSIDE_SUBSCRIPTION = 1;
 
+    public static $version = 3.0;
     public static $last_error;
 
     private static $ready = false;
@@ -49,6 +50,7 @@ class kolab_storage
 
         $rcmail = rcube::get_instance();
         self::$config = $rcmail->config;
+        self::$version = $rcmail->config->get('kolab_format_version', self::$version);
         self::$imap = $rcmail->get_storage();
         self::$ready = class_exists('kolabformat') &&
             (self::$imap->get_capability('METADATA') || self::$imap->get_capability('ANNOTATEMORE') || self::$imap->get_capability('ANNOTATEMORE2'));
diff --git a/plugins/libkolab/lib/kolab_storage_folder.php b/plugins/libkolab/lib/kolab_storage_folder.php
index 08bf6690..e92a6fae 100644
--- a/plugins/libkolab/lib/kolab_storage_folder.php
+++ b/plugins/libkolab/lib/kolab_storage_folder.php
@@ -466,39 +466,27 @@ class kolab_storage_folder
             return false;
         }
 
-        $format = kolab_format::factory($object_type);
-
-        if (is_a($format, 'PEAR_Error'))
-            return false;
-
         // check kolab format version
-        $mime_version = $headers->others['x-kolab-mime-version'];
-        if (empty($mime_version)) {
+        $format_version = $headers->others['x-kolab-mime-version'];
+        if (empty($format_version)) {
             list($xmltype, $subtype) = explode('.', $object_type);
             $xmlhead = substr($xml, 0, 512);
 
             // detect old Kolab 2.0 format
             if (strpos($xmlhead, '<' . $xmltype) !== false && strpos($xmlhead, 'xmlns=') === false)
-                $mime_version = 2.0;
+                $format_version = 2.0;
             else
-                $mime_version = 3.0; // assume 3.0
+                $format_version = 3.0; // assume 3.0
         }
 
-        if ($mime_version <= 2.0) {
-            // read Kolab 2.0 format
-            $handler = class_exists('Horde_Kolab_Format') ? Horde_Kolab_Format::factory('XML', $xmltype, array('subtype' => $subtype)) : null;
-            if (!is_object($handler) || is_a($handler, 'PEAR_Error')) {
-                return false;
-            }
+        // get Kolab format handler for the given type
+        $format = kolab_format::factory($object_type, $format_version);
 
-            // XML-to-array
-            $object = $handler->load($xml);
-            $format->fromkolab2($object);
-        }
-        else {
-            // load Kolab 3 format using libkolabxml
-            $format->load($xml);
-        }
+        if (is_a($format, 'PEAR_Error'))
+            return false;
+
+        // load Kolab object from XML part
+        $format->load($xml);
 
         if ($format->is_valid()) {
             $object = $format->to_array();
@@ -696,13 +684,13 @@ class kolab_storage_folder
 
         // create new kolab_format instance
         if (!$format)
-            $format = kolab_format::factory($type);
+            $format = kolab_format::factory($type, kolab_storage::$version);
 
         if (PEAR::isError($format))
             return false;
 
         $format->set($object);
-        $xml = $format->write();
+        $xml = $format->write(kolab_storage::$version);
         $object['uid'] = $format->uid;  // read UID from format
         $object['_formatobj'] = $format;
 
@@ -721,7 +709,7 @@ class kolab_storage_folder
         }
         $headers['Date'] = date('r');
         $headers['X-Kolab-Type'] = kolab_format::KTYPE_PREFIX . $type;
-        $headers['X-Kolab-Mime-Version'] = kolab_format::VERSION;
+        $headers['X-Kolab-Mime-Version'] = kolab_storage::$version;
         $headers['Subject'] = $object['uid'];
 //        $headers['Message-ID'] = $rcmail->gen_message_id();
         $headers['User-Agent'] = $rcmail->config->get('useragent');