diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 92459738..4545d02b 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -219,6 +219,7 @@ class calendar extends rcube_plugin
     $this->register_handler('plugin.attendees_freebusy_table', array($this->ui, 'attendees_freebusy_table'));
     $this->register_handler('plugin.edit_attendees_notify', array($this->ui, 'edit_attendees_notify'));
     $this->register_handler('plugin.edit_recurring_warning', array($this->ui, 'recurring_event_warning'));
+    $this->register_handler('plugin.event_rsvp_buttons', array($this->ui, 'event_rsvp_buttons'));
     $this->register_handler('plugin.searchform', array($this->rc->output, 'search_form'));  // use generic method from rcube_template
 
     $this->rc->output->add_label('low','normal','high','delete','cancel','uploading','noemailwarning');
@@ -228,6 +229,13 @@ class calendar extends rcube_plugin
 
     $this->rc->output->set_env('calendar_driver', $this->rc->config->get('calendar_driver'), false);
 
+    $view = get_input_value('view', RCUBE_INPUT_GPC);
+    if (in_array($view, array('agendaWeek', 'agendaDay', 'month', 'table')))
+      $this->rc->output->set_env('view', $view);
+    
+    if ($date = get_input_value('date', RCUBE_INPUT_GPC))
+      $this->rc->output->set_env('date', $date);
+
     $this->rc->output->send("calendar.calendar");
   }
 
@@ -534,7 +542,7 @@ class calendar extends rcube_plugin
         }
         $reload = true;
         break;
-      
+        
       case "edit":
         $this->prepare_event($event, $action);
         if ($success = $this->driver->edit_event($event))
@@ -592,6 +600,27 @@ class calendar extends rcube_plugin
 
         break;
 
+      case "rsvp":
+        $ev = $this->driver->get_event($event);
+        $ev['attendees'] = $event['attendees'];
+        $event = $ev;
+
+        if ($success = $this->driver->edit_event($event)) {
+          $status = get_input_value('status', RCUBE_INPUT_GPC);
+          $organizer = null;
+          foreach ($event['attendees'] as $i => $attendee) {
+            if ($attendee['role'] == 'ORGANIZER') {
+              $organizer = $attendee;
+              break;
+            }
+          }
+          if ($organizer && $this->send_itip_message($event, 'REPLY', $organizer, 'itipsubject' . $status, 'itipmailbody' . $status))
+            $this->rc->output->command('display_message', $this->gettext(array('name' => 'sentresponseto', 'vars' => array('mailto' => $organizer['name']))), 'confirmation');
+          else
+            $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
+        }
+        break;
+
       case "dismiss":
         foreach (explode(',', $event['id']) as $id)
           $success |= $this->driver->dismiss_alarm($id, $event['snooze']);
@@ -740,8 +769,12 @@ class calendar extends rcube_plugin
     
     // get user identity to create default attendee
     if ($this->ui->screen == 'calendar') {
-      $identity = $this->rc->user->get_identity();
-      $settings['event_owner'] = array('name' => $identity['name'], 'email' => $identity['email']);
+      foreach ($this->rc->user->list_identities() as $rec) {
+        if (!$identity)
+          $identity = $rec;
+        $identity['emails'][] = $rec['email'];
+      }
+      $settings['identity'] = array('name' => $identity['name'], 'email' => $identity['email'], 'emails' => ';' . join(';', $identity['emails']));
     }
 
     return $settings;
@@ -1254,8 +1287,8 @@ class calendar extends rcube_plugin
       
       // set owner as organizer if yet missing
       if (!$organizer && $owner !== false) {
-        $event['attendees'][$i]['role'] = 'ORGANIZER';
-        unset($event['attendees'][$i]['rsvp']);
+        $event['attendees'][$owner]['role'] = 'ORGANIZER';
+        unset($event['attendees'][$owner]['rsvp']);
       }
       else if (!$organizer && $identity['email'] && $action == 'new') {
         array_unshift($event['attendees'], array('role' => 'ORGANIZER', 'name' => $identity['name'], 'email' => $identity['email'], 'status' => 'ACCEPTED'));
@@ -1280,83 +1313,35 @@ class calendar extends rcube_plugin
    */
   private function notify_attendees($event, $old, $action = 'edit')
   {
-    $sent = 0;
-    $myself = $this->rc->user->get_identity();
-    $from = rcube_idn_to_ascii($myself['email']);
-    $sender = format_email_recipient($from, $myself['name']);
-    
-    // compose multipart message using PEAR:Mail_Mime
-    $message = new Mail_mime("\r\n");
-    $message->setParam('text_encoding', 'quoted-printable');
-    $message->setParam('head_encoding', 'quoted-printable');
-    $message->setParam('head_charset', RCMAIL_CHARSET);
-    $message->setParam('text_charset', RCMAIL_CHARSET . ";\r\n format=flowed");
-    
-    // compose common headers array
-    $headers = array(
-      'From' => $sender,
-      'Date' => rcmail_user_date(),
-      'Message-ID' => rcmail_gen_message_id(),
-      'X-Sender' => $from,
-    );
-    if ($agent = $this->rc->config->get('useragent'))
-      $headers['User-Agent'] = $agent;
-    
     if ($action == 'remove') {
       $event['cancelled'] = true;
       $is_cancelled = true;
     }
-    
-    // attach ics file for this event
-    $this->load_ical();
-    $vcal = $this->ical->export(array($event), 'REQUEST');
-    $message->addAttachment($vcal, 'text/calendar', 'event.ics', false, '8bit', 'attachment', RCMAIL_CHARSET);
-    
+
+    // compose multipart message using PEAR:Mail_Mime
+    $method = $action == 'remove' ? 'CANCEL' : 'REQUEST';
+    $message = $this->compose_itip_message($event, $method);
+
     // list existing attendees from $old event
     $old_attendees = array();
     foreach ((array)$old['attendees'] as $attendee) {
       $old_attendees[] = $attendee['email'];
     }
-    
-    // compose a list of all event attendees
-    $attendees_list = array();
-    foreach ((array)$event['attendees'] as $attendee) {
-      $attendees_list[] = ($attendee['name'] && $attendee['email']) ?
-        $attendee['name'] . ' <' . $attendee['email'] . '>' :
-        ($attendee['name'] ? $attendee['name'] : $attendee['email']);
-    }
-    
+
     // send to every attendee
+    $sent = 0;
     foreach ((array)$event['attendees'] as $attendee) {
       // skip myself for obvious reasons
       if (!$attendee['email'] || $attendee['email'] == $myself['email'])
         continue;
       
+      // which template to use for mail text
       $is_new = !in_array($attendee['email'], $old_attendees);
-      $mailto = rcube_idn_to_ascii($attendee['email']);
-      $headers['To'] = format_email_recipient($mailto, $attendee['name']);
-      
-      $headers['Subject'] = $this->gettext(array(
-        'name' => $is_cancelled ? 'eventcancelsubject' : ($is_new ? 'invitationsubject' : ($event['title'] ? 'eventupdatesubject':'eventupdatesubjectempty')),
-        'vars' => array('title' => $event['title']),
-      ));
-      
-      // compose message body
-      $body = $this->gettext(array(
-        'name' => $is_cancelled ? 'eventcancelmailbody' : ($is_new ? 'invitationmailbody' : 'eventupdatemailbody'),
-        'vars' => array(
-          'title' => $event['title'],
-          'date' => $this->event_date_text($event),
-          'attendees' => join(', ', $attendees_list),
-          'organizer' => $myself['name'],
-        )
-      ));
-      
-      $message->headers($headers);
-      $message->setTXTBody(rcube_message::format_flowed($body, 79));
+      $bodytext = $is_cancelled ? 'eventcancelmailbody' : ($is_new ? 'invitationmailbody' : 'eventupdatemailbody');
+      $subject  = $is_cancelled ? 'eventcancelsubject'  : ($is_new ? 'invitationsubject' : ($event['title'] ? 'eventupdatesubject':'eventupdatesubjectempty'));
       
       // finally send the message
-      if (rcmail_deliver_message($message, $from, $mailto, $smtp_error))
+      if ($this->send_itip_message($event, $method, $attendee, $subject, $bodytext, $message))
         $sent++;
       else
         $sent = -100;
@@ -1577,21 +1562,76 @@ class calendar extends rcube_plugin
       if (empty($events))
           continue;
 
-      // TODO: show more iTip options like (accept, deny, etc.)
+      // show a box for every event in the file
       foreach ($events as $idx => $event) {
-        $prefix = $this->ical->method == 'REPLY' ? $this->gettext('itipreply') : '';
-        
-        // add box below messsage body
-        $html .= html::p('calendar-invitebox',
-          html::span('eventtitle', Q($prefix . $event['title'])) . ' ' .
-          html::span('eventdate', Q('(' . $this->event_date_text($event) . ')')) . ' ' .
-          html::tag('input', array(
+        // define buttons according to method
+        if ($this->ical->method == 'REPLY') {
+          $title = $this->gettext('itipreply');
+          $buttons = html::tag('input', array(
             'type' => 'button',
             'class' => 'button',
             'onclick' => "rcube_calendar.add_event_from_mail('" . JQ($mime_id.':'.$idx) . "', '" . JQ($event['title']) . "')",
-            'value' => $this->ical->method == 'REPLY' ? $this->gettext('updateattendeestatus') : $this->gettext('importtocalendar'),
-          ))
-        );
+            'value' => $this->gettext('updateattendeestatus'),
+          ));
+        }
+        else if ($this->ical->method == 'REQUEST') {
+          $title = $event['SEQUENCE'] > 0 ? $this->gettext('itipupdate') : $this->gettext('itipinvitation');
+          
+          // TODO: check for a copy in my calendar in order to show the right options
+          if (!$event['SEQUENCE']) {
+            foreach (array('accepted','tentative','declined') as $method) {
+              $buttons .= html::tag('input', array(
+                'type' => 'button',
+                'class' => 'button',
+                'onclick' => "rcube_calendar.add_event_from_mail('" . JQ($mime_id.':'.$idx) . "', '$method')",
+                'value' => $this->gettext('itip' . $method),
+              ));
+            }
+          }
+          else {
+            $buttons = html::tag('input', array(
+              'type' => 'button',
+              'class' => 'button',
+              'onclick' => "rcube_calendar.add_event_from_mail('" . JQ($mime_id.':'.$idx) . "')",
+              'value' => $this->gettext('importtocalendar'),
+            ));
+          }
+        }
+        else if ($this->ical->method == 'CANCEL') {
+          $title = $this->gettext('itipcancellation');
+          $buttons = html::tag('input', array(
+            'type' => 'button',
+            'class' => 'button',
+            'onclick' => "rcube_calendar.remove_event_from_mail('" . JQ($event['uid']) . "', '" . JQ($event['title']) . "')",
+            'value' => $this->gettext('importtocalendar'),
+          ));
+        }
+        else {
+          $buttons = html::tag('input', array(
+            'type' => 'button',
+            'class' => 'button',
+            'onclick' => "rcube_calendar.add_event_from_mail('" . JQ($mime_id.':'.$idx) . "')",
+            'value' => $this->gettext('importtocalendar'),
+          ));
+        }
+        
+        // show event details in a table
+        $table = new html_table(array('cols' => 2, 'border' => 0, 'class' => 'calendar-eventdetails'));
+        $table->add('ititle', $title);
+        $table->add('title', Q($event['title']));
+        $table->add('label', $this->gettext('date'));
+        $table->add('location', Q($this->event_date_text($event)));
+        if ($event['location']) {
+          $table->add('label', $this->gettext('location'));
+          $table->add('location', Q($event['location']));
+        }
+        
+        // add box below messsage body
+        $html .= html::div('calendar-invitebox', $table->show() . html::div('rsvp-buttons', $buttons));
+        
+        // limit listing
+        if ($idx >= 3)
+          break;
       }
     }
 
@@ -1604,6 +1644,7 @@ class calendar extends rcube_plugin
     return $p;
   }
   
+  
   /**
    * Handler for POST request to import an event attached to a mail message
    */
@@ -1612,6 +1653,7 @@ class calendar extends rcube_plugin
     $uid = get_input_value('_uid', RCUBE_INPUT_POST);
     $mbox = get_input_value('_mbox', RCUBE_INPUT_POST);
     $mime_id = get_input_value('_part', RCUBE_INPUT_POST);
+    $status = get_input_value('_status', RCUBE_INPUT_POST);
     $charset = RCMAIL_CHARSET;
     
     // establish imap connection
@@ -1646,8 +1688,25 @@ class calendar extends rcube_plugin
           }
         }
       }
+
+      // update my attendee status according to submitted method
+      if (!empty($status)) {
+        $emails = array($this->rc->user->get_username());
+        foreach ($this->rc->user->list_identities() as $identity)
+          $emails[] = $identity['email'];
+        $organizer = null;
+        foreach ($event['attendees'] as $i => $attendee) {
+          if ($attendee['role'] == 'ORGANIZER') {
+            $organizer = $attendee;
+          }
+          else if ($attendee['email'] && in_array($attendee['email'], $emails)) {
+            $event['attendees'][$i]['status'] = strtoupper($status);
+          }
+        }
+      }
       
-      if ($calendar && !$calendar['readonly']) {
+      // save to calendar
+      if ($calendar && !$calendar['readonly'] && $status != 'declined') {
         $event['id'] = $event['uid'];
         $event['calendar'] = $calendar['id'];
         
@@ -1701,6 +1760,8 @@ class calendar extends rcube_plugin
           $success = $this->driver->new_event($event);
         }
       }
+      else if ($status == 'declined')
+        $error_msg = null;
       else
         $error_msg = $this->gettext('nowritecalendarfound');
     }
@@ -1708,14 +1769,117 @@ class calendar extends rcube_plugin
     if ($success) {
       $message = $this->ical->method == 'REPLY' ? 'attendeupdateesuccess' : 'importedsuccessfully';
       $this->rc->output->command('display_message', $this->gettext(array('name' => $message, 'vars' => array('calendar' => $calendar['name']))), 'confirmation');
+      $error_msg = null;
     }
-    else
+    else if ($error_msg)
       $this->rc->output->command('display_message', $error_msg, 'error');
 
+
+    // send iTip reply
+    if ($this->ical->method == 'REQUEST' && $organizer && !$error_msg) {
+      if ($this->send_itip_message($event, 'REPLY', $organizer, 'itipsubject' . $status, 'itipmailbody' . $status))
+        $this->rc->output->command('display_message', $this->gettext(array('name' => 'sentresponseto', 'vars' => array('mailto' => $organizer['name']))), 'confirmation');
+      else
+        $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
+    }
+
     $this->rc->output->send();
   }
 
 
+  /**
+   * Send an iTip mail message
+   *
+   * @param array   Event object to send
+   * @param string  iTip method (REQUEST|REPLY|CANCEL)
+   * @param array   Hash array with recipient data (name, email)
+   * @param string  Mail subject
+   * @param string  Mail body text label
+   * @param object  Mail_mime object with message data
+   * @return boolean True on success, false on failure
+   */
+  public function send_itip_message($event, $method, $recipient, $subject, $bodytext, $message = null)
+  {
+    if (!$message)
+      $message = $this->compose_itip_message($event, $method);
+    
+    $myself = $this->rc->user->get_identity();
+    $mailto = rcube_idn_to_ascii($recipient['email']);
+    
+    $headers = $message->headers();
+    $headers['To'] = format_email_recipient($mailto, $recipient['name']);
+    $headers['Subject'] = $this->gettext(array(
+      'name' => $subject,
+      'vars' => array('title' => $event['title'], 'name' => ($myself['name'] ? $myself['name'] : $myself['email']))
+    ));
+    
+    // compose a list of all event attendees
+    $attendees_list = array();
+    foreach ((array)$event['attendees'] as $attendee) {
+      $attendees_list[] = ($attendee['name'] && $attendee['email']) ?
+        $attendee['name'] . ' <' . $attendee['email'] . '>' :
+        ($attendee['name'] ? $attendee['name'] : $attendee['email']);
+    }
+    
+    $mailbody = $this->gettext(array(
+      'name' => $bodytext,
+      'vars' => array(
+        'title' => $event['title'],
+        'date' => $this->event_date_text($event),
+        'attendees' => join(', ', $attendees_list),
+        'sender' => $myself['name'] ? $myself['name'] : $myself['email'],
+        'organizer' => $myself['name'],
+      )
+    ));
+    
+    $message->headers($headers);
+    $message->setTXTBody(rcube_message::format_flowed($mailbody, 79));
+    
+    // finally send the message
+    return rcmail_deliver_message($message, $headers['X-Sender'], $mailto, $smtp_error);
+  }
+
+  /**
+   * Helper function to build a Mail_mime object to send an iTip message
+   *
+   * @param array   Event object to send
+   * @param string  iTip method (REQUEST|REPLY|CANCEL)
+   * @return object Mail_mime object with message data
+   */
+  private function compose_itip_message($event, $method)
+  {
+    $myself = $this->rc->user->get_identity();
+    $from = rcube_idn_to_ascii($myself['email']);
+    $sender = format_email_recipient($from, $myself['name']);
+    
+    // compose multipart message using PEAR:Mail_Mime
+    $message = new Mail_mime("\r\n");
+    $message->setParam('text_encoding', 'quoted-printable');
+    $message->setParam('head_encoding', 'quoted-printable');
+    $message->setParam('head_charset', RCMAIL_CHARSET);
+    $message->setParam('text_charset', RCMAIL_CHARSET . ";\r\n format=flowed");
+    
+    // compose common headers array
+    $headers = array(
+      'From' => $sender,
+      'Date' => rcmail_user_date(),
+      'Message-ID' => rcmail_gen_message_id(),
+      'X-Sender' => $from,
+    );
+    if ($agent = $this->rc->config->get('useragent'))
+      $headers['User-Agent'] = $agent;
+    
+    $message->headers($headers);
+    
+    // attach ics file for this event
+    $this->load_ical();
+    $vcal = $this->ical->export(array($event), $method);
+    $message->addAttachment($vcal, 'text/calendar', 'event.ics', false, '8bit', 'attachment', RCMAIL_CHARSET);
+    
+    return $message;
+  }
+
+
   /**
    * Checks if specified message part is a vcalendar data
    *
diff --git a/plugins/calendar/calendar_base.js b/plugins/calendar/calendar_base.js
index 056bc5b1..f22e4689 100644
--- a/plugins/calendar/calendar_base.js
+++ b/plugins/calendar/calendar_base.js
@@ -159,10 +159,15 @@ function rcube_calendar(settings)
 }
 
 // static methods
-rcube_calendar.add_event_from_mail = function(mime_id, title)
+rcube_calendar.add_event_from_mail = function(mime_id, status)
 {
   var lock = rcmail.set_busy(true, 'loading');
-  rcmail.http_post('calendar/mailimportevent', '_uid='+rcmail.env.uid+'&_mbox='+urlencode(rcmail.env.mailbox)+'&_part='+urlencode(mime_id), lock);
+  rcmail.http_post('calendar/mailimportevent', {
+      '_uid': rcmail.env.uid,
+      '_mbox': rcmail.env.mailbox,
+      '_part': mime_id,
+      '_status': status
+    }, lock);
   return false;
 };
 
diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 07e3e64c..34b35693 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -137,7 +137,17 @@ function rcube_calendar_ui(settings)
     // check if the event has 'real' attendees, excluding the current user
     var has_attendees = function(event)
     {
-      return (event.attendees && (event.attendees.length > 1 || event.attendees[0].email != settings.event_owner.email));
+      return (event.attendees && (event.attendees.length > 1 || event.attendees[0].email != settings.identity.email));
+    };
+    
+    // check if the current user is the organizer
+    var is_organizer = function(event)
+    {
+      for (var i=0; event.attendees && i < event.attendees.length; i++) {
+        if (event.attendees[i].role == 'ORGANIZER' && event.attendees[i].email && event.attendees[i].email == settings.identity.email)
+          return true;
+      }
+      return !event.id;
     };
 
     // create a nice human-readable string for the date/time range
@@ -233,6 +243,7 @@ function rcube_calendar_ui(settings)
     {
       var $dialog = $("#eventshow");
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { editable:false };
+      me.selected_event = event;
       
       $dialog.find('div.event-section, div.event-line').hide();
       $('#event-title').html(Q(event.title)).show();
@@ -279,27 +290,37 @@ function rcube_calendar_ui(settings)
       
       // list event attendees
       if (calendar.attendees && event.attendees) {
-        var data, dispname, organizer = false, html = '';
+        var dispname, html = '';
+        if (event.organizer) {
+          dispname = Q(data.name || data.email);
+          html += '<span class="attendee organizer">' + dispname + '</span> ';
+        }
+        
+        var data, rsvp = false;
         for (var j=0; j < event.attendees.length; j++) {
           data = event.attendees[j];
           dispname = Q(data.name || data.email);
-          if (data.email)
+          if (data.email) {
             dispname = '<a href="mailto:' + data.email + '" title="' + Q(data.email) + '" class="mailtolink">' + dispname + '</a>';
-          html += '<span class="attendee ' + String(data.role == 'ORGANIZER' ? 'organizer' : data.status).toLowerCase() + '">' + dispname + '</span> ';
-          if (data.role == 'ORGANIZER')
-            organizer = true;
+            if (data.status == 'NEEDS-ACTION' || data.status == 'TENTATIVE' && settings.identity.emails.indexOf(';'+data.email) >= 0)
+              rsvp = true;
+          }
+          html += '<span class="attendee ' + data.status.toLowerCase() + '">' + dispname + '</span> ';
+          
           // stop listing attendees
           if (j == 7 && event.attendees.length >= 7) {
             html += ' <em>' + rcmail.gettext('andnmore', 'calendar').replace('$nr', event.attendees.length - j - 1) + '</em>';
             break;
           }
         }
-        if (html && event.attendees.length > 1 || !organizer) {
+        if (html) {
           $('#event-attendees').show()
             .children('.event-text')
             .html(html)
             .find('a.mailtolink').click(function(e) { rcmail.redirect(rcmail.url('mail/compose', { _to:this.href.substr(7) })); return false; });
         }
+        
+        $('#event-rsvp')[(rsvp?'show':'hide')]();
       }
       
       var buttons = {};
@@ -468,9 +489,10 @@ function rcube_calendar_ui(settings)
         $('#edit-recurring-warning').hide();
 
       // init attendees tab
+      var organizer = is_organizer(event);
       event_attendees = [];
       attendees_list = $('#edit-attendees-table > tbody').html('');
-      $('#edit-attendees-notify')[(notify.checked?'show':'hide')]();
+      $('#edit-attendees-notify')[(notify.checked && organizer ? 'show' : 'hide')]();
 
       var load_attendees_tab = function()
       {
@@ -479,6 +501,7 @@ function rcube_calendar_ui(settings)
             add_attendee(event.attendees[j], true);
         }
 
+        $('#edit-attendees-form .attendees-invitebox')[(organizer?'show':'hide')]();
         $('#edit-attendee-schedule')[(calendar.freebusy?'show':'hide')]();
       };
 
@@ -557,11 +580,11 @@ function rcube_calendar_ui(settings)
         });
         
         // don't submit attendees if only myself is added as organizer
-        if (data.attendees.length == 1 && data.attendees[0].role == 'ORGANIZER' && data.attendees[0].email == settings.event_owner.email)
+        if (data.attendees.length == 1 && data.attendees[0].role == 'ORGANIZER' && data.attendees[0].email == settings.identity.email)
           data.attendees = [];
         
         // tell server to send notifications
-        if (data.attendees.length && ((event.id && notify.checked) || (!event.id && invite.checked))) {
+        if (data.attendees.length && organizer && ((event.id && notify.checked) || (!event.id && invite.checked))) {
           data.notify = 1;
         }
 
@@ -734,8 +757,8 @@ function rcube_calendar_ui(settings)
         .bind('click.roleicons', function(e){
           // toggle attendee status upon click on icon
           if (e.target.id && e.target.id.match(/rcmlia(.+)/)) {
-            var attendee, domid = RegExp.$1, roles = [ 'ORGANIZER', 'REQ-PARTICIPANT', 'OPT-PARTICIPANT', 'CHAIR' ];
-            if ((attendee = freebusy_ui.attendees[domid])) {
+            var attendee, domid = RegExp.$1, roles = [ 'REQ-PARTICIPANT', 'OPT-PARTICIPANT', 'CHAIR' ];
+            if ((attendee = freebusy_ui.attendees[domid]) && attendee.role != 'ORGANIZER') {
               var req = attendee.role != 'OPT-PARTICIPANT';
               var j = $.inArray(attendee.role, roles);
               j = (j+1) % roles.length;
@@ -1288,13 +1311,15 @@ function rcube_calendar_ui(settings)
         dispname = '<a href="mailto:' + data.email + '" title="' + Q(data.email) + '" class="mailtolink">' + dispname + '</a>';
       
       // role selection
-      var opts = {
-        'ORGANIZER': rcmail.gettext('calendar.roleorganizer'),
-        'REQ-PARTICIPANT': rcmail.gettext('calendar.rolerequired'),
-        'OPT-PARTICIPANT': rcmail.gettext('calendar.roleoptional'),
-        'CHAIR': rcmail.gettext('calendar.roleresource')
-      };
-      var select = '<select class="edit-attendee-role">';
+      var organizer = data.role == 'ORGANIZER';
+      var opts = {};
+      if (organizer)
+        opts.ORGANIZER = rcmail.gettext('calendar.roleorganizer');
+      opts['REQ-PARTICIPANT'] = rcmail.gettext('calendar.rolerequired');
+      opts['OPT-PARTICIPANT'] = rcmail.gettext('calendar.roleoptional');
+      opts['CHAIR'] =  rcmail.gettext('calendar.roleresource');
+      
+      var select = '<select class="edit-attendee-role"' + (organizer ? ' disabled="true"' : '') + '>';
       for (var r in opts)
         select += '<option value="'+ r +'" class="' + r.toLowerCase() + '"' + (data.role == r ? ' selected="selected"' : '') +'>' + Q(opts[r]) + '</option>';
       select += '</select>';
@@ -1310,7 +1335,7 @@ function rcube_calendar_ui(settings)
         '<td class="name">' + dispname + '</td>' +
         '<td class="availability"><img src="./program/blank.gif" class="availabilityicon ' + avail + '" /></td>' +
         '<td class="confirmstate"><span class="' + String(data.status).toLowerCase() + '">' + Q(data.status) + '</span></td>' +
-        '<td class="options">' + dellink + '</td>';
+        '<td class="options">' + (organizer ? '' : dellink) + '</td>';
       
       var tr = $('<tr>')
         .addClass(String(data.role).toLowerCase())
@@ -1372,6 +1397,24 @@ function rcube_calendar_ui(settings)
       event_attendees = $.grep(event_attendees, function(data){ return (data.name != id && data.email != id) });
     };
     
+    // when the user accepts or declines an event invitation
+    var event_rsvp = function(response)
+    {
+      if (me.selected_event && me.selected_event.attendees && response) {
+        // update attendee status
+        for (var data, i=0; i < me.selected_event.attendees.length; i++) {
+          data = me.selected_event.attendees[i];
+          if (settings.identity.emails.indexOf(';'+data.email) >= 0)
+            data.status = response.toUpperCase();
+        }
+        event_show_dialog(me.selected_event);
+        
+        // submit status change to server
+        me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
+        rcmail.http_post('event', { action:'rsvp', e:me.selected_event, status:response });
+      }
+    }
+    
     // post the given event data to server
     var update_event = function(action, data)
     {
@@ -1413,14 +1456,20 @@ function rcube_calendar_ui(settings)
     var update_event_confirm = function(action, event, data)
     {
       if (!data) data = event;
-      var html = '';
+      var notify = false, html = '';
       
       // event has attendees, ask whether to notify them
       if (has_attendees(event)) {
-        html += '<div class="message">' +
-          '<label><input class="confirm-attendees-donotify" type="checkbox" ' + (action != 'remove' ? ' checked="checked"' : '') + ' value="1" name="notify" />&nbsp;' +
-          rcmail.gettext((action == 'remove' ? 'sendcancellation' : 'sendnotifications'), 'calendar') + 
-          '</label></div>';
+        if (is_organizer(event)) {
+          notify = true;
+          html += '<div class="message">' +
+            '<label><input class="confirm-attendees-donotify" type="checkbox" ' + (action != 'remove' ? ' checked="checked"' : '') + ' value="1" name="notify" />&nbsp;' +
+            rcmail.gettext((action == 'remove' ? 'sendcancellation' : 'sendnotifications'), 'calendar') + 
+            '</label></div>';
+        }
+        else {
+          html += '<div class="message">' + rcmail.gettext('localchangeswarning', 'calendar') + '</div>';
+        }
       }
       
       // recurring event: user needs to select the savemode
@@ -1442,7 +1491,7 @@ function rcube_calendar_ui(settings)
         $dialog.find('a.button').button().click(function(e){
           data.savemode = String(this.href).replace(/.+#/, '');
           if ($dialog.find('input.confirm-attendees-donotify').get(0))
-            data.notify = $dialog.find('input.confirm-attendees-donotify').get(0).checked ? 1 : 0;
+            data.notify = notify && $dialog.find('input.confirm-attendees-donotify').get(0).checked ? 1 : 0;
           update_event(action, data);
           $dialog.dialog("destroy").hide();
           return false;
@@ -1459,7 +1508,7 @@ function rcube_calendar_ui(settings)
           buttons.push({
             text: rcmail.gettext((action == 'remove' ? 'remove' : 'save'), 'calendar'),
             click: function() {
-              data.notify = $dialog.find('input.confirm-attendees-donotify').get(0).checked ? 1 : 0;
+              data.notify = notify && $dialog.find('input.confirm-attendees-donotify').get(0).checked ? 1 : 0;
               update_event(action, data);
               $(this).dialog("close");
             }
@@ -1814,6 +1863,9 @@ function rcube_calendar_ui(settings)
     if (settings.default_calendar && this.calendars[settings.default_calendar] && !this.calendars[settings.default_calendar].readonly)
       this.selected_calendar = settings.default_calendar;
     
+    var viewdate = new Date();
+    if (rcmail.env.date)
+      viewdate.setTime(fromunixtime(rcmail.env.date));
     
     // initalize the fullCalendar plugin
     var fc = $('#calendar').fullCalendar({
@@ -1823,6 +1875,9 @@ function rcube_calendar_ui(settings)
         right: 'agendaDay,agendaWeek,month,table'
       },
       aspectRatio: 1,
+      date: viewdate.getDate(),
+      month: viewdate.getMonth(),
+      year: viewdate.getFullYear(),
       ignoreTimezone: true,  // will treat the given date strings as in local (browser's) timezone
       height: $('#main').height(),
       eventSources: event_sources,
@@ -1856,7 +1911,7 @@ function rcube_calendar_ui(settings)
       listPage: 1,  // advance one day in agenda view
       listRange: settings['agenda_range'],
       tableCols: ['handle', 'date', 'time', 'title', 'location'],
-      defaultView: settings['default_view'],
+      defaultView: rcmail.env.view || settings['default_view'],
       allDayText: rcmail.gettext('all-day', 'calendar'),
       buttonText: {
         prev: (bw.ie6 ? '&nbsp;&lt;&lt;&nbsp;' : '&nbsp;&#9668;&nbsp;'),
@@ -2104,7 +2159,7 @@ function rcube_calendar_ui(settings)
               update_freebusy_status(me.selected_event);
             // add current user as organizer if non added yet
             if (!event_attendees.length)
-              add_attendee($.extend({ role:'ORGANIZER' }, settings.event_owner));
+              add_attendee($.extend({ role:'ORGANIZER' }, settings.identity));
           }
         }
       });
@@ -2198,6 +2253,10 @@ function rcube_calendar_ui(settings)
         if (this.checked)
           $('<style type="text/css" id="workinghourscss"> td.offhours { opacity:0.3; filter:alpha(opacity=30) } </style>').appendTo('head');
       });
+      
+      $('#event-rsvp input.button').click(function(){
+        event_rsvp($(this).attr('rel'))
+      })
 
       // hide event dialog when clicking somewhere into document
       $(document).bind('mousedown', dialog_check);
diff --git a/plugins/calendar/drivers/calendar_driver.php b/plugins/calendar/drivers/calendar_driver.php
index b1cd580c..77501fd3 100644
--- a/plugins/calendar/drivers/calendar_driver.php
+++ b/plugins/calendar/drivers/calendar_driver.php
@@ -61,10 +61,11 @@
  *              'id' => 'Attachment identifier'
  *   ),
  * 'deleted_attachments' => array(), // array of attachment identifiers to delete when event is updated
+ *     'organizer' => array('name' => 'Organizer name', 'email' => ''),
  *     'attendees' => array(   // List of event participants
  *            'name' => 'Participant name',
  *           'email' => 'Participant e-mail address',  // used as identifier
- *            'role' => 'ORGANIZER|REQ-PARTICIPANT|OPT-PARTICIPANT|CHAIR',
+ *            'role' => 'REQ-PARTICIPANT|OPT-PARTICIPANT|CHAIR',
  *          'status' => 'NEEDS-ACTION|UNKNOWN|ACCEPTED|TENTATIVE|DECLINED'
  *            'rsvp' => true|false,
  *    ),
diff --git a/plugins/calendar/lib/calendar_ical.php b/plugins/calendar/lib/calendar_ical.php
index e31d4ae3..372958d7 100644
--- a/plugins/calendar/lib/calendar_ical.php
+++ b/plugins/calendar/lib/calendar_ical.php
@@ -181,6 +181,10 @@ class calendar_ical
           $event['recurrence_id'] = $this->_date2time($attr['value']);
           break;
         
+        case 'SEQUENCE':
+          $event['sequence'] = intval($attr['value']);
+          break;
+        
         case 'DESCRIPTION':
         case 'LOCATION':
           $event[strtolower($attr['name'])] = $attr['value'];
diff --git a/plugins/calendar/lib/calendar_ui.php b/plugins/calendar/lib/calendar_ui.php
index 25c48daa..c0015f45 100644
--- a/plugins/calendar/lib/calendar_ui.php
+++ b/plugins/calendar/lib/calendar_ui.php
@@ -627,5 +627,22 @@ class calendar_ui
     
     return $table->show($attrib);
   }
+  
+  
+  function event_rsvp_buttons($attrib = array())
+  {
+    foreach (array('accepted','tentative','declined') as $method) {
+      $buttons .= html::tag('input', array(
+        'type' => 'button',
+        'class' => 'button',
+        'rel' => $method,
+        'value' => $this->calendar->gettext('itip' . $method),
+      ));
+    }
+    
+    return html::div($attrib,
+      html::div('label', $this->calendar->gettext('acceptinvitation')) .
+      html::div('rsvp-buttons', $buttons));
+  }
 
 }
diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
index 26f7949c..c31fb6b0 100644
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -122,9 +122,22 @@ $labels['eventcancelsubject'] = '"$title" has been canceled';
 $labels['eventcancelmailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\nThe event has been cancelled by \$organizer.\n\nPlease find attached an iCalendar file with the updated event details.";
 
 // invitation handling
-$labels['itipreply'] = 'Reply to ';
+$labels['itipinvitation'] = 'Invitation to';
+$labels['itipupdate'] = 'Update of';
+$labels['itipcancellation'] = 'Cancelled:';
+$labels['itipreply'] = 'Reply to';
+$labels['itipaccepted'] = 'Accept';
+$labels['itiptentative'] = 'Maybe';
+$labels['itipdeclined'] = 'Decline';
+$labels['itipsubjectaccepted'] = '"$title" has been accepted by $name';
+$labels['itipsubjecttentative'] = '"$title" has been tentatively accepted by $name';
+$labels['itipsubjectdeclined'] = '"$title" has been declined by $name';
+$labels['itipmailbodyaccepted'] = "\$sender has accepted the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
+$labels['itipmailbodytentative'] = "\$sender has tentatively accepted the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
+$labels['itipmailbodydeclined'] = "\$sender has declined the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
 $labels['importtocalendar'] = 'Save to my calendar';
 $labels['updateattendeestatus'] = 'Update the participant\'s status';
+$labels['acceptinvitation'] = 'Do you accept this invitation?';
 
 // event dialog tabs
 $labels['tabsummary'] = 'Summary';
@@ -149,6 +162,9 @@ $labels['newerversionexists'] = 'A newer version of this event already exists! A
 $labels['nowritecalendarfound'] = 'No calendar found to save the event';
 $labels['importedsuccessfully'] = 'The event was successfully added to \'$calendar\'';
 $labels['attendeupdateesuccess'] = 'Successfully updated the participant\'s status';
+$labels['itipresponseerror'] = 'Failed to send the response to this event invitation';
+$labels['sentresponseto'] = 'Successfully sent invitation response to $mailto';
+$labels['localchangeswarning'] = 'You are about to make changes that will only be reflected on your personal calendar';
 
 // recurrence form
 $labels['repeat'] = 'Repeat';
diff --git a/plugins/calendar/skins/default/calendar.css b/plugins/calendar/skins/default/calendar.css
index 3de7a7f8..210936c7 100644
--- a/plugins/calendar/skins/default/calendar.css
+++ b/plugins/calendar/skins/default/calendar.css
@@ -527,6 +527,7 @@ td.topalign {
 	min-width: 5em;
 }
 
+#event-rsvp,
 #edit-attendees-notify {
 	margin: 0.3em 0;
 	padding: 0.5em;
@@ -1091,15 +1092,31 @@ fieldset #calendarcategories div {
 
 /* Invitation UI in mail */
 
-p.calendar-invitebox {
+div.calendar-invitebox {
 	min-height: 20px;
 	margin: 5px 8px;
-	padding: 6px 6px 6px 34px;
+	padding: 3px 6px 6px 34px;
 	border: 1px solid #C2D071;
-	background: url('images/calendar.png') 6px 3px no-repeat #F7FDCB;
+	background: url('images/calendar.png') 6px 5px no-repeat #F7FDCB;
 }
 
-p.calendar-invitebox input.button {
-	margin-left: 1em;
-	font-size: 11px;
+div.calendar-invitebox td.ititle {
+	font-weight: bold;
+	padding-right: 0.5em;
+}
+
+div.calendar-invitebox td.label {
+	color: #666;
+	padding-right: 1em;
+}
+
+#event-rsvp .rsvp-buttons,
+div.calendar-invitebox .rsvp-buttons {
+	margin-top: 0.5em;
+}
+
+#event-rsvp input.button,
+div.calendar-invitebox input.button {
+	font-size: 11px;
+	margin-right: 0.5em;
 }
diff --git a/plugins/calendar/skins/default/templates/calendar.html b/plugins/calendar/skins/default/templates/calendar.html
index 4dfb01be..87253b72 100644
--- a/plugins/calendar/skins/default/templates/calendar.html
+++ b/plugins/calendar/skins/default/templates/calendar.html
@@ -83,6 +83,8 @@
     <label><roundcube:label name="attachments" /></label>
     <div class="event-text attachments-list"></div>
   </div>
+  
+  <roundcube:object name="plugin.event_rsvp_buttons" id="event-rsvp" style="display:none" />
 </div>
 
 <div id="eventedit" class="uidialog">