diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 1d40efe5..fc0069d4 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -725,9 +725,29 @@ class calendar extends rcube_plugin
           $this->rc->output->command('plugin.destroy_source', array('id' => $cal['id']));
         break;
       case "subscribe":
-        if (!$this->driver->subscribe_calendar($cal))
+        if (!$this->driver->subscribe_calendar($cal, intval(get_input_value('perm', RCUBE_INPUT_GPC))))
           $this->rc->output->show_message($this->gettext('errorsaving'), 'error');
         return;
+      case "search":
+        $results = array();
+        $color_mode = $this->rc->config->get('calendar_event_coloring', $this->defaults['calendar_event_coloring']);
+        foreach ((array)$this->driver->search_calendars(get_input_value('q', RCUBE_INPUT_GPC), get_input_value('source', RCUBE_INPUT_GPC)) as $id => $prop) {
+          $editname = $prop['editname'];
+          unset($prop['editname']);  // force full name to be displayed
+          $prop['active'] = false;
+
+          // let the UI generate HTML and CSS representation for this calendar
+          $html = $this->ui->calendar_list_item($id, $prop, $jsenv);
+          $cal = $jsenv[$id];
+          $cal['editname'] = $editname;
+          $cal['html'] = $html;
+          if (!empty($prop['color']))
+            $cal['css'] = $this->ui->calendar_css_classes($id, $prop, $color_mode);
+
+          $results[] = $cal;
+        }
+        $this->rc->output->command('multi_thread_http_response', $results, get_input_value('_reqid', RCUBE_INPUT_GPC));
+        return;
     }
     
     if ($success)
diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 2a8a8d2b..4db85937 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -39,6 +39,7 @@ function rcube_calendar_ui(settings)
     this.selected_calendar = null;
     this.search_request = null;
     this.saving_lock;
+    this.calendars = {};
 
 
     /***  private vars  ***/
@@ -52,6 +53,9 @@ function rcube_calendar_ui(settings)
     var event_defaults = { free_busy:'busy', alarms:'' };
     var event_attendees = [];
     var calendars_list;
+    var calenders_search_list;
+    var calenders_search_container;
+    var search_calendars = {};
     var attendees_list;
     var resources_list;
     var resources_treelist;
@@ -2667,16 +2671,79 @@ function rcube_calendar_ui(settings)
       this.selected_calendar = id;
     };
 
+    // render the results for calendar list search
+    var calendar_search_results = function(results)
+    {
+      if (results.length) {
+        // create treelist widget to present the search results
+        if (!calenders_search_list) {
+          calenders_search_container = $('<div class="searchresults"></div>')
+            .html('<h2 class="boxtitle">' + rcmail.gettext('calsearchresults','calendar') + '</h2>')
+            .insertAfter(rcmail.gui_objects.calendarslist);
 
-    /***  startup code  ***/
+          calenders_search_list = new rcube_treelist_widget('<ul class="treelist listing"></ul>', {
+            id_prefix: 'rcmlical',
+            selectable: false
+          });
 
-    // create list of event sources AKA calendars
-    this.calendars = {};
-    var id, li, cal, active, color, brightness, event_sources = [];
-    for (id in rcmail.env.calendars) {
-      cal = rcmail.env.calendars[id];
-      this.calendars[id] = $.extend({
-        url: "./?_task=calendar&_action=load_events&source="+escape(id),
+          // register click handler on search result's checkboxes to select the given calendar for listing
+          calenders_search_list.container
+            .appendTo(calenders_search_container)
+            .on('click', 'input[type=checkbox]', function(e){
+              var li = $(this).closest('li'),
+                id = li.attr('id').replace(/^rcmlical/, ''),
+                prop = search_calendars[id],
+                parent_id = prop.parent || null;
+
+              if (!this.checked)
+                return;
+
+              // find parent node and insert at the right place
+              if (parent_id && $('#rcmlical'+parent_id, rcmail.gui_objects.calendarslist).length) {
+                prop.listname = prop.editname;
+                li.children().first().find('.calname').html(Q(prop.listname));
+              }
+
+              // move this calendar to the calendars_list widget
+              calendars_list.insert({
+                id: id,
+                classes: [],
+                html: li.children().first()
+              }, parent_id, parent_id ? true : false);
+
+              search_calendars[id].active = true;
+              add_calendar_source(prop);
+              li.remove();
+
+              // add css classes related to this calendar to document
+              if (cal.css) {
+                $('<style type="text/css"></style>')
+                  .html(cal.css)
+                  .appendTo('head');
+              }
+            });
+        }
+
+        for (var cal, i=0; i < results.length; i++) {
+          cal = results[i];
+          search_calendars[cal.id] = cal;
+          $('<li>')
+            .attr('id', 'rcmlical' + cal.id)
+            .html(cal.html)
+            .appendTo(calenders_search_list.container);
+        }
+
+        calenders_search_container.show();
+      }
+    };
+
+    // register the given calendar to the current view
+    var add_calendar_source = function(cal)
+    {
+      var color, brightness, select, id = cal.id;
+
+      me.calendars[id] = $.extend({
+        url: rcmail.url('calendar/load_events', { source: id }),
         editable: !cal.readonly,
         className: 'fc-event-cal-'+id,
         id: id
@@ -2689,18 +2756,40 @@ function rcube_calendar_ui(settings)
           // http://javascriptrules.com/2009/08/05/css-color-brightness-contrast-using-javascript/
           brightness = (parseInt(RegExp.$1, 16) * 299 + parseInt(RegExp.$2, 16) * 587 + parseInt(RegExp.$3, 16) * 114) / 1000;
           if (brightness > 125)
-            this.calendars[id].textColor = 'black';
+            me.calendars[id].textColor = 'black';
         }
+
+        me.calendars[id].color = color;
       }
 
-      this.calendars[id].color = color;
-
-      if ((active = cal.active || false)) {
-        event_sources.push(this.calendars[id]);
+      if (fc && cal.active) {
+        fc.fullCalendar('addEventSource', me.calendars[id]);
+        rcmail.http_post('calendar', { action:'subscribe', c:{ id:id, active:cal.active?1:0 } });
       }
 
+      // insert to #calendar-select options if writeable
+      select = $('#edit-calendar');
+      if (fc && !cal.readonly && select.length && !select.find('option[value="'+id+'"]').length) {
+        $('<option>').attr('value', id).text(Q(cal.name)).appendTo(select);
+      }
+    }
+
+
+    /***  startup code  ***/
+
+    // create list of event sources AKA calendars
+    var id, cal, active, event_sources = [];
+    for (id in rcmail.env.calendars) {
+      cal = rcmail.env.calendars[id];
+      active = cal.active || false;
+      add_calendar_source(cal);
+
       // check active calendars
-      $('#rcmlical'+id+' > .calendar input').data('id', id).get(0).checked = active;
+      $('#rcmlical'+id+' > .calendar input').get(0).checked = active;
+
+      if (active) {
+        event_sources.push(this.calendars[id]);
+      }
 
       if (!cal.readonly && !this.selected_calendar) {
         this.selected_calendar = id;
@@ -2720,12 +2809,32 @@ function rcube_calendar_ui(settings)
       rcmail.enable_command('calendar-remove', !me.calendars[node.id].readonly);
     });
     calendars_list.addEventListener('search', function(search){
-      console.log(search);
+      // hide search results
+      if (calenders_search_list) {
+        calenders_search_container.hide();
+        calenders_search_list.reset();
+      }
+      search_calendars = {};
+
+      // send search request(s) to server
+      if (search.query && search.execute) {
+        var sources = [ 'folders' /*, 'users'*/ ];
+        var reqid = rcmail.multi_thread_http_request({
+          items: sources,
+          threads: rcmail.env.autocomplete_threads || 1,
+          action:  'calendar/calendar',
+          postdata: { action:'search', q:search.query, source:'%s' },
+          lock: rcmail.display_message(rcmail.get_label('searching'), 'loading'),
+          onresponse: calendar_search_results
+        });
+
+        listsearch_data = { id:reqid, sources:sources.slice(), num:sources.length };
+      }
     });
 
     // init (delegate) event handler on calendar list checkboxes
     $(rcmail.gui_objects.calendarslist).on('click', 'input[type=checkbox]', function(e){
-      var id = $(this).data('id');
+      var id = this.value;
       if (me.calendars[id]) {  // add or remove event source on click
         var action;
         if (this.checked) {
diff --git a/plugins/calendar/drivers/calendar_driver.php b/plugins/calendar/drivers/calendar_driver.php
index c5eff9d6..9fb6ffb8 100644
--- a/plugins/calendar/drivers/calendar_driver.php
+++ b/plugins/calendar/drivers/calendar_driver.php
@@ -165,6 +165,15 @@ abstract class calendar_driver
    */
   abstract function remove_calendar($prop);
 
+  /**
+   * Search for shared or otherwise not listed calendars the user has access
+   *
+   * @param string Search string
+   * @param string Section/source to search
+   * @return array List of calendars
+   */
+  abstract function search_calendars($query, $source);
+
   /**
    * Add a single event to the database
    *
diff --git a/plugins/calendar/drivers/database/database_driver.php b/plugins/calendar/drivers/database/database_driver.php
index 059cd1d9..d0e6b7b8 100644
--- a/plugins/calendar/drivers/database/database_driver.php
+++ b/plugins/calendar/drivers/database/database_driver.php
@@ -247,6 +247,19 @@ class database_driver extends calendar_driver
     return $this->rc->db->affected_rows($query);
   }
 
+  /**
+   * Search for shared or otherwise not listed calendars the user has access
+   *
+   * @param string Search string
+   * @param string Section/source to search
+   * @return array List of calendars
+   */
+  public function search_calendars($query, $source)
+  {
+    // not implemented
+    return array();
+  }
+
   /**
    * Add a single event to the database
    *
diff --git a/plugins/calendar/drivers/kolab/kolab_calendar.php b/plugins/calendar/drivers/kolab/kolab_calendar.php
index 46fbed90..5feed234 100644
--- a/plugins/calendar/drivers/kolab/kolab_calendar.php
+++ b/plugins/calendar/drivers/kolab/kolab_calendar.php
@@ -52,11 +52,12 @@ class kolab_calendar
       $this->imap_folder = $this->name = $imap_folder;
 
     // ID is derrived from folder name
-    $this->id = kolab_storage::folder_id($this->imap_folder);
+    $this->id = kolab_storage::folder_id($this->imap_folder, true);
+    $old_id   = kolab_storage::folder_id($this->imap_folder, false);
 
     // fetch objects from the given IMAP folder
     $this->storage = kolab_storage::get_folder($this->imap_folder);
-    $this->ready = $this->storage && !PEAR::isError($this->storage);
+    $this->ready = $this->storage && !PEAR::isError($this->storage) && $this->storage->type !== null;
 
     // Set readonly and alarms flags according to folder permissions
     if ($this->ready) {
@@ -76,6 +77,8 @@ class kolab_calendar
       $prefs = $this->cal->rc->config->get('kolab_calendars', array());
       if (isset($prefs[$this->id]['showalarms']))
         $this->alarms = $prefs[$this->id]['showalarms'];
+      else if (isset($prefs[$old_id]['showalarms']))
+        $this->alarms = $prefs[$old_id]['showalarms'];
     }
   }
 
diff --git a/plugins/calendar/drivers/kolab/kolab_driver.php b/plugins/calendar/drivers/kolab/kolab_driver.php
index 974a3d3d..786556f0 100644
--- a/plugins/calendar/drivers/kolab/kolab_driver.php
+++ b/plugins/calendar/drivers/kolab/kolab_driver.php
@@ -62,6 +62,9 @@ class kolab_driver extends calendar_driver
         $this->alarm_types = array('DISPLAY');
         $this->alarm_absolute = false;
     }
+
+    // calendar uses fully encoded identifiers
+    kolab_storage::$encode_ids = true;
   }
 
 
@@ -117,6 +120,9 @@ class kolab_driver extends calendar_driver
     foreach ($folders as $id => $cal) {
       $fullname = $cal->get_name();
       $listname = kolab_storage::folder_displayname($fullname, $names);
+      $imap_path = explode('/', $cal->name);
+      $topname = array_pop($imap_path);
+      $parent_id = kolab_storage::folder_id(join('/', $imap_path), true);
 
       // special handling for virtual folders
       if ($cal->virtual) {
@@ -143,6 +149,7 @@ class kolab_driver extends calendar_driver
           'active'   => $cal->storage->is_active(),
           'owner'    => $cal->get_owner(),
           'children' => true,  // TODO: determine if that folder indeed has child folders
+          'parent'   => $parent_id,
           'caldavurl' => $cal->get_caldav_url(),
         );
       }
@@ -212,6 +219,26 @@ class kolab_driver extends calendar_driver
     return $calendars;
   }
 
+
+  /**
+   * Get the kolab_calendar instance for the given calendar ID
+   *
+   * @param string Calendar identifier (encoded imap folder name)
+   * @return object kolab_calendar Object nor null if calendar doesn't exist
+   */
+  protected function get_calendar($id)
+  {
+    // create calendar object if necesary
+    if (!$this->calendars[$id] && $id !== self::BIRTHDAY_CALENDAR_ID) {
+      $foldername = kolab_storage::id_decode($id);
+      $calendar = new kolab_calendar($foldername, $this->cal);
+      if ($calendar->ready)
+        $this->calendars[$calendar->id] = $calendar;
+    }
+
+    return $this->calendars[$id];
+  }
+
   /**
    * Create a new calendar assigned to the current user
    *
@@ -257,7 +284,7 @@ class kolab_driver extends calendar_driver
    */
   public function edit_calendar($prop)
   {
-    if ($prop['id'] && ($cal = $this->calendars[$prop['id']])) {
+    if ($prop['id'] && ($cal = $this->get_calendar($prop['id']))) {
       $prop['oldname'] = $cal->get_realname();
       $newfolder = kolab_storage::folder_update($prop);
 
@@ -297,9 +324,10 @@ class kolab_driver extends calendar_driver
    *
    * @see calendar_driver::subscribe_calendar()
    */
-  public function subscribe_calendar($prop)
+  public function subscribe_calendar($prop, $permanent = false)
   {
-    if ($prop['id'] && ($cal = $this->calendars[$prop['id']])) {
+    if ($prop['id'] && ($cal = $this->get_calendar($prop['id']))) {
+      if ($permanent) $cal->storage->subscribe($prop['active']);
       return $cal->storage->activate($prop['active']);
     }
     else {
@@ -321,8 +349,9 @@ class kolab_driver extends calendar_driver
    */
   public function remove_calendar($prop)
   {
-    if ($prop['id'] && ($cal = $this->calendars[$prop['id']])) {
+    if ($prop['id'] && ($cal = $this->get_calendar($prop['id']))) {
       $folder = $cal->get_realname();
+      // TODO: unsubscribe if no admin rights
       if (kolab_storage::folder_delete($folder)) {
         // remove color in user prefs (temp. solution)
         $prefs['kolab_calendars'] = $this->rc->config->get('kolab_calendars', array());
@@ -339,6 +368,51 @@ class kolab_driver extends calendar_driver
   }
 
 
+  /**
+   * Search for shared or otherwise not listed calendars the user has access
+   *
+   * @param string Search string
+   * @param string Section/source to search
+   * @return array List of calendars
+   */
+  public function search_calendars($query, $source)
+  {
+    if (!kolab_storage::setup())
+      return array();
+
+    $this->calendars = array();
+    $imap = $this->rc->get_storage();
+
+    // find unsubscribed IMAP folders that have "event" type
+    if ($source == 'folders') {
+      $folders = array();
+      foreach ((array)kolab_storage::list_folders('', '*', 'event', false, $folderdata) as $foldername) {
+        // FIXME: only consider the last part of the folder path for searching?
+        $realname = strtolower(rcube_charset::convert($foldername, 'UTF7-IMAP'));
+        if (strpos($realname, $query) !== false &&
+            !kolab_storage::folder_is_subscribed($foldername, true) &&
+            $imap->folder_namespace($foldername) != 'other'
+          ) {
+          $folders[$foldername] = new kolab_storage_folder($foldername, $folderdata[$foldername]);
+        }
+      }
+
+      foreach ($folders as $folder) {
+        $calendar = new kolab_calendar($folder->name, $this->cal);
+        $this->calendars[$calendar->id] = $calendar;
+      }
+    }
+    else if ($source == 'users') {
+      // TODO: implement this
+    }
+
+    // don't list the birthday calendar
+    $this->rc->config->set('calendar_contact_birthdays', false);
+
+    return $this->list_calendars();
+  }
+
+
   /**
    * Fetch a single event
    *
@@ -356,7 +430,7 @@ class kolab_driver extends calendar_driver
     }
 
     if ($cal) {
-      if ($storage = $this->calendars[$cal]) {
+      if ($storage = $this->get_calendar($cal)) {
         return $storage->get_event($id);
       }
     }
@@ -383,7 +457,7 @@ class kolab_driver extends calendar_driver
       return false;
 
     $cid = $event['calendar'] ? $event['calendar'] : reset(array_keys($this->calendars));
-    if ($storage = $this->calendars[$cid]) {
+    if ($storage = $this->get_calendar($cid)) {
       // handle attachments to add
       if (!empty($event['attachments'])) {
         foreach ($event['attachments'] as $idx => $attachment) {
@@ -425,7 +499,7 @@ class kolab_driver extends calendar_driver
    */
   public function move_event($event)
   {
-    if (($storage = $this->calendars[$event['calendar']]) && ($ev = $storage->get_event($event['id']))) {
+    if (($storage = $this->get_calendar($event['calendar'])) && ($ev = $storage->get_event($event['id']))) {
       unset($ev['sequence']);
       return $this->update_event($event + $ev);
     }
@@ -441,7 +515,7 @@ class kolab_driver extends calendar_driver
    */
   public function resize_event($event)
   {
-    if (($storage = $this->calendars[$event['calendar']]) && ($ev = $storage->get_event($event['id']))) {
+    if (($storage = $this->get_calendar($event['calendar'])) && ($ev = $storage->get_event($event['id']))) {
       unset($ev['sequence']);
       return $this->update_event($event + $ev);
     }
@@ -463,7 +537,7 @@ class kolab_driver extends calendar_driver
     $success = false;
     $savemode = $event['_savemode'];
 
-    if (($storage = $this->calendars[$event['calendar']]) && ($event = $storage->get_event($event['id']))) {
+    if (($storage = $this->get_calendar($event['calendar'])) && ($event = $storage->get_event($event['id']))) {
       $event['_savemode'] = $savemode;
       $savemode = 'all';
       $master = $event;
@@ -566,7 +640,7 @@ class kolab_driver extends calendar_driver
    */
   public function restore_event($event)
   {
-    if ($storage = $this->calendars[$event['calendar']]) {
+    if ($storage = $this->get_calendar($event['calendar'])) {
       if (!empty($_SESSION['calendar_restore_event_data']))
         $success = $storage->update_event($_SESSION['calendar_restore_event_data']);
       else
@@ -586,12 +660,12 @@ class kolab_driver extends calendar_driver
    */
   private function update_event($event)
   {
-    if (!($storage = $this->calendars[$event['calendar']]))
+    if (!($storage = $this->get_calendar($event['calendar'])))
       return false;
 
     // move event to another folder/calendar
     if ($event['_fromcalendar'] && $event['_fromcalendar'] != $event['calendar']) {
-      if (!($fromcalendar = $this->calendars[$event['_fromcalendar']]))
+      if (!($fromcalendar = $this->get_calendar($event['_fromcalendar'])))
         return false;
 
       if ($event['_savemode'] != 'new') {
@@ -780,18 +854,19 @@ class kolab_driver extends calendar_driver
   {
     if ($calendars && is_string($calendars))
       $calendars = explode(',', $calendars);
+    else if (!$calendars)
+      $calendars = array_keys($this->calendars);
 
     $query = array();
     if ($modifiedsince)
       $query[] = array('changed', '>=', $modifiedsince);
 
     $events = $categories = array();
-    foreach (array_keys($this->calendars) as $cid) {
-      if ($calendars && !in_array($cid, $calendars))
-        continue;
-
-      $events = array_merge($events, $this->calendars[$cid]->list_events($start, $end, $search, $virtual, $query));
-      $categories += $this->calendars[$cid]->categories;
+    foreach ($calendars as $cid) {
+      if ($storage = $this->get_calendar($cid)) {
+        $events = array_merge($events, $storage->list_events($start, $end, $search, $virtual, $query));
+        $categories += $storage->categories;
+      }
     }
 
     // add events from the address books birthday calendar
@@ -928,7 +1003,7 @@ class kolab_driver extends calendar_driver
    */
   public function list_attachments($event)
   {
-    if (!($storage = $this->calendars[$event['calendar']]))
+    if (!($storage = $this->get_calendar($event['calendar'])))
       return false;
 
     $event = $storage->get_event($event['id']);
@@ -941,7 +1016,7 @@ class kolab_driver extends calendar_driver
    */
   public function get_attachment($id, $event)
   {
-    if (!($storage = $this->calendars[$event['calendar']]))
+    if (!($storage = $this->get_calendar($event['calendar'])))
       return false;
 
     $event = $storage->get_event($event['id']);
@@ -963,7 +1038,7 @@ class kolab_driver extends calendar_driver
    */
   public function get_attachment_body($id, $event)
   {
-    if (!($cal = $this->calendars[$event['calendar']]))
+    if (!($cal = $this->get_calendar($event['calendar'])))
       return false;
 
     return $cal->storage->get_attachment($event['id'], $id);
@@ -1080,7 +1155,7 @@ class kolab_driver extends calendar_driver
     ignore_user_abort(true);
 
     $cal = get_input_value('source', RCUBE_INPUT_GPC);
-    if (!($cal = $this->calendars[$cal]))
+    if (!($cal = $this->get_calendar($cal)))
       return false;
 
     // trigger updates on folder
@@ -1275,7 +1350,7 @@ class kolab_driver extends calendar_driver
   public function calendar_acl_form()
   {
     $calid = get_input_value('_id', RCUBE_INPUT_GPC);
-    if ($calid && ($cal = $this->calendars[$calid])) {
+    if ($calid && ($cal = $this->get_calendar($calid))) {
       $folder = $cal->get_realname(); // UTF7
       $color  = $cal->get_color();
     }
diff --git a/plugins/calendar/lib/calendar_ui.php b/plugins/calendar/lib/calendar_ui.php
index 117b9242..69ba9c2d 100644
--- a/plugins/calendar/lib/calendar_ui.php
+++ b/plugins/calendar/lib/calendar_ui.php
@@ -157,31 +157,41 @@ class calendar_ui
     foreach ((array)$calendars as $id => $prop) {
       if (!$prop['color'])
         continue;
-      $color = $prop['color'];
-      $class = 'cal-' . asciiwords($id, true);
-      $css .= "li.$class, #eventshow .$class { color: #$color }\n";
-      if ($mode != 1) {
-        if ($mode == 3) {
-          $css .= ".fc-event-$class .fc-event-bg {";
-          $css .= " opacity: 0.9;";
-          $css .= " filter: alpha(opacity=90);";
-        }
-        else {
-          $css .= ".fc-event-$class, ";
-          $css .= ".fc-event-$class .fc-event-inner {";
-        }
-        if (!$attrib['printmode'])
-          $css .= " background-color: #$color;";
-        if ($mode % 2 == 0)
-        $css .= " border-color: #$color;";
-        $css .= "}\n";
-      }
-      $css .= ".$class .handle { background-color: #$color; }";
+      $css .= $this->calendar_css_classes($id, $prop, $mode);
     }
     
     return html::tag('style', array('type' => 'text/css'), $css);
   }
 
+  /**
+   *
+   */
+  public function calendar_css_classes($id, $prop, $mode)
+  {
+    $color = $prop['color'];
+    $class = 'cal-' . asciiwords($id, true);
+    $css .= "li.$class, #eventshow .$class { color: #$color }\n";
+
+    if ($mode != 1) {
+      if ($mode == 3) {
+        $css .= ".fc-event-$class .fc-event-bg {";
+        $css .= " opacity: 0.9;";
+        $css .= " filter: alpha(opacity=90);";
+      }
+      else {
+        $css .= ".fc-event-$class, ";
+        $css .= ".fc-event-$class .fc-event-inner {";
+      }
+      if (!$attrib['printmode'])
+        $css .= " background-color: #$color;";
+      if ($mode % 2 == 0)
+      $css .= " border-color: #$color;";
+      $css .= "}\n";
+    }
+
+    return $css . ".$class .handle { background-color: #$color; }\n";
+  }
+
   /**
    *
    */
@@ -222,9 +232,9 @@ class calendar_ui
 
     return html::tag('ul', $attrib, $html, html::$common_attrib);
   }
-  
+
   /**
-   * Return html for a structured list &lt;ul&gt; for the mailbox tree
+   * Return html for a structured list <ul> for the folder tree
    */
   public function list_tree_html(&$node, &$data, &$jsenv, $attrib)
   {
@@ -255,7 +265,7 @@ class calendar_ui
   /**
    * Helper method to build a calendar list item (HTML content and js data)
    */
-  protected function calendar_list_item($id, $prop, &$jsenv)
+  public function calendar_list_item($id, $prop, &$jsenv)
   {
     unset($prop['user_id']);
     $prop['alarms']      = $this->cal->driver->alarms;
@@ -283,7 +293,7 @@ class calendar_ui
     if (!$attrib['activeonly'] || $prop['active']) {
       $content = html::div($class,
         ($prop['virtual'] ? '' : html::tag('input', array('type' => 'checkbox', 'name' => '_cal[]', 'value' => $id, 'checked' => $prop['active']), '') .
-        html::span('handle', '&nbsp;')) .
+        html::span(array('class' => 'handle', 'style' => "background-color: #" . ($prop['color'] ?: 'f00')), '&nbsp;')) .
         html::span(array('class' => 'calname', 'title' => $title), $prop['editname'] ? Q($prop['editname']) : $prop['listname'])
       );
     }
diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
index 4621feb6..b6e7ff25 100644
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -86,6 +86,7 @@ $labels['nmonthsback'] = '$nr months back';
 $labels['showurl'] = 'Show calendar URL';
 $labels['showurldescription'] = 'Use the following address to access (read only) your calendar from other applications. You can copy and paste this into any calendar software that supports the iCal format.';
 $labels['caldavurldescription'] = 'Copy this address to a <a href="http://en.wikipedia.org/wiki/CalDAV" target="_blank">CalDAV</a> client application (e.g. Evolution or Mozilla Thunderbird) to fully synchronize this specific calendar with your computer or mobile device.';
+$labels['calsearchresults'] = 'Additional Results';
 
 // agenda view
 $labels['listrange'] = 'Range to display:';
diff --git a/plugins/calendar/skins/larry/calendar.css b/plugins/calendar/skins/larry/calendar.css
index 1ffaea8b..01a4c3d6 100644
--- a/plugins/calendar/skins/larry/calendar.css
+++ b/plugins/calendar/skins/larry/calendar.css
@@ -168,27 +168,23 @@ pre {
 	top: 68px;
 }
 
-#calendarslist li {
+#calendars .treelist li {
 	margin: 0;
 	position: relative;
 }
 
-#calendarslist li label {
-	display: block;
-}
-
-#calendarslist li div.folder,
-#calendarslist li div.calendar {
+#calendars .treelist li div.folder,
+#calendars .treelist li div.calendar {
 	position: relative;
 	height: 28px;
 }
 
-#calendarslist li div.virtual {
+#calendars .treelist li div.virtual {
 	height: 22px;
 }
 
 
-#calendarslist li span.calname {
+#calendars .treelist li span.calname {
 	display: block;
 	padding: 0px 30px 2px 2px;
 	position: absolute;
@@ -203,17 +199,17 @@ pre {
 	color: #004458;
 }
 
-#calendarslist li div.virtual > span.calname {
+#calendars .treelist li div.virtual > span.calname {
 	color: #aaa;
 	top: 4px;
 	left: 20px;
 }
 
-#calendarslist.flat li span.calname {
+#calendars .treelist.flat li span.calname {
 	left: 24px;
 }
 
-#calendarslist li span.handle {
+#calendars .treelist li span.handle {
 	display: inline-block;
 	position: absolute;
 	top: 8px;
@@ -229,66 +225,77 @@ pre {
 	box-shadow: inset 0px 0 1px 1px rgba(0, 0, 0, 0.3);
 }
 
-#calendarslist li input {
+#calendars .treelist li input {
 	position: absolute;
 	top: 5px;
 	left: 18px;
 }
 
-#calendarslist li div.treetoggle {
+#calendars .treelist li div.treetoggle {
 	top: 8px;
 }
 
-#calendarslist li.virtual div.treetoggle {
+#calendars .treelist li.virtual div.treetoggle {
 	top: 6px;
 }
 
-#calendarslist.flat li input {
+#calendars .treelist.flat li input {
 	left: 4px;
 }
 
-#calendarslist ul li div.folder,
-#calendarslist ul li div.calendar {
+#calendars .treelist ul li div.folder,
+#calendars .treelist ul li div.calendar {
 	margin-left: 16px;
 }
 
-#calendarslist ul ul li div.folder,
-#calendarslist ul ul li div.calendar {
+#calendars .treelist ul ul li div.folder,
+#calendars .treelist ul ul li div.calendar {
 	margin-left: 32px;
 }
 
-#calendarslist ul ul ul li div.folder,
-#calendarslist ul ul ul li div.calendar {
+#calendars .treelist ul ul ul li div.folder,
+#calendars .treelist ul ul ul li div.calendar {
 	margin-left: 48px;
 }
 
-#calendarslist li.selected {
+#calendars .treelist li.selected {
 	background-color: #c7e3ef;
 }
 
-#calendarslist li.selected > span.calname {
+#calendars .treelist li.selected > span.calname {
 	font-weight: bold;
 }
 
-#calendarslist div.readonly span.calname {
+#calendars .treelist div.readonly span.calname {
 	background-position: right -20px;
 }
-
-#calendarslist div.other span.calname {
+/*
+#calendars .treelist div.other span.calname {
 	background-position: right -38px;
 }
 
-#calendarslist div.other.readonly span.calname {
+#calendars .treelist div.other.readonly span.calname {
 	background-position: right -56px;
 }
 
-#calendarslist div.shared span.calname {
+#calendars .treelist div.shared span.calname {
 	background-position: right -74px;
 }
 
-#calendarslist div.shared.readonly span.calname {
+#calendars .treelist div.shared.readonly span.calname {
 	background-position: right -92px;
 }
+*/
+
+#calendars .searchresults {
+	background: #b0ccd7;
+	margin-top: 8px;
+}
+
+#calendars .searchresults .boxtitle {
+	background: none;
+	padding: 2px 8px 2px 8px;
+}
 
 #calfeedurl,
 #caldavurl {
diff --git a/plugins/kolab_addressbook/kolab_addressbook.php b/plugins/kolab_addressbook/kolab_addressbook.php
index c8dd59e7..f28d4966 100644
--- a/plugins/kolab_addressbook/kolab_addressbook.php
+++ b/plugins/kolab_addressbook/kolab_addressbook.php
@@ -247,7 +247,7 @@ class kolab_addressbook extends rcube_plugin
             $names = array();
             foreach ($folders as $folder) {
                 // create instance of rcube_contacts
-                $abook_id = kolab_storage::folder_id($folder->name);
+                $abook_id = kolab_storage::folder_id($folder->name, false);
                 $abook = new rcube_kolab_contacts($folder->name);
                 $this->sources[$abook_id] = $abook;
             }
diff --git a/plugins/libkolab/lib/kolab_storage.php b/plugins/libkolab/lib/kolab_storage.php
index 9504e8fa..55526fd6 100644
--- a/plugins/libkolab/lib/kolab_storage.php
+++ b/plugins/libkolab/lib/kolab_storage.php
@@ -7,7 +7,7 @@
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  * @author Aleksander Machniak <machniak@kolabsys.com>
  *
- * Copyright (C) 2012, Kolab Systems AG <contact@kolabsys.com>
+ * Copyright (C) 2012-2014, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -37,6 +37,7 @@ class kolab_storage
 
     public static $version = '3.0';
     public static $last_error;
+    public static $encode_ids = false;
 
     private static $ready = false;
     private static $subscriptions;
@@ -226,13 +227,39 @@ class kolab_storage
     /**
      * Creates folder ID from folder name
      *
-     * @param string $folder Folder name (UTF7-IMAP)
-     *
+     * @param string  $folder Folder name (UTF7-IMAP)
+     * @param boolean $enc    Use lossless encoding
      * @return string Folder ID string
      */
-    public static function folder_id($folder)
+    public static function folder_id($folder, $enc = null)
     {
-        return asciiwords(strtr($folder, '/.-', '___'));
+        return $enc == true || ($enc === null && self::$encode_ids) ?
+            self::id_encode($folder) :
+            asciiwords(strtr($folder, '/.-', '___'));
+    }
+
+
+    /**
+     * Encode the given ID to a safe ascii representation
+     *
+     * @param string $id Arbitrary identifier string
+     *
+     * @return string Ascii representation
+     */
+    public static function id_encode($id)
+    {
+        return rtrim(strtr(base64_encode($id), '+/', '-_'), '=');
+    }
+
+    /**
+     * Convert the given identifier back to it's raw value
+     *
+     * @param string $id Ascii identifier
+     * @return string Raw identifier string
+     */
+    public static function id_decode($id)
+    {
+      return base64_decode(str_pad(strtr($id, '-_', '+/'), strlen($id) % 4, '=', STR_PAD_RIGHT));
     }
 
 
@@ -665,11 +692,16 @@ class kolab_storage
         if (!$filter) {
             // Get ALL folders list, standard way
             if ($subscribed) {
-                return self::$imap->list_folders_subscribed($root, $mbox);
+                $folders = self::$imap->list_folders_subscribed($root, $mbox);
+                // add temporarily subscribed folders
+                if (is_array($_SESSION['kolab_subscribed_folders']))
+                    $folders = array_unique(array_merge($folders, $_SESSION['kolab_subscribed_folders']));
             }
             else {
-                return self::$imap->list_folders($root, $mbox);
+                $folders = self::$imap->list_folders($root, $mbox);
             }
+
+            return $folders;
         }
 
         $prefix = $root . $mbox;
@@ -696,6 +728,10 @@ class kolab_storage
         // Get folders list
         if ($subscribed) {
             $folders = self::$imap->list_folders_subscribed($root, $mbox);
+
+            // add temporarily subscribed folders
+            if (is_array($_SESSION['kolab_subscribed_folders']))
+                $folders = array_unique(array_merge($folders, $_SESSION['kolab_subscribed_folders']));
         }
         else {
             $folders = self::$imap->list_folders($root, $mbox);
@@ -903,17 +939,19 @@ class kolab_storage
      * Check subscription status of this folder
      *
      * @param string $folder Folder name
+     * @param boolean $temp  Include temporary/session subscriptions
      *
      * @return boolean True if subscribed, false if not
      */
-    public static function folder_is_subscribed($folder)
+    public static function folder_is_subscribed($folder, $temp = false)
     {
         if (self::$subscriptions === null) {
             self::setup();
             self::$subscriptions = self::$imap->list_folders_subscribed();
         }
 
-        return in_array($folder, self::$subscriptions);
+        return in_array($folder, self::$subscriptions) ||
+            ($temp && in_array($folder, (array)$_SESSION['kolab_subscribed_folders']));
     }
 
 
@@ -921,14 +959,25 @@ class kolab_storage
      * Change subscription status of this folder
      *
      * @param string $folder Folder name
+     * @param boolean $temp  Only subscribe temporarily for the current session
      *
      * @return True on success, false on error
      */
-    public static function folder_subscribe($folder)
+    public static function folder_subscribe($folder, $temp = false)
     {
         self::setup();
 
-        if (self::$imap->subscribe($folder)) {
+        // temporary/session subscription
+        if ($temp) {
+            if (self::folder_is_subscribed($folder)) {
+                return true;
+            }
+            else if (!is_array($_SESSION['kolab_subscribed_folders']) || !in_array($folder, $_SESSION['kolab_subscribed_folders'])) {
+                $_SESSION['kolab_subscribed_folders'][] = $folder;
+                return true;
+            }
+        }
+        else if (self::$imap->subscribe($folder)) {
             self::$subscriptions === null;
             return true;
         }
@@ -981,6 +1030,8 @@ class kolab_storage
      */
     public static function folder_activate($folder)
     {
+        // activation implies temporary subscription
+        self::folder_subscribe($folder, true);
         return self::set_state($folder, true);
     }
 
@@ -994,6 +1045,11 @@ class kolab_storage
      */
     public static function folder_deactivate($folder)
     {
+        // remove from temp subscriptions
+        if (is_array($_SESSION['kolab_subscribed_folders']) && ($i = array_search($folder, $_SESSION['kolab_subscribed_folders'])) !== false) {
+            unset($_SESSION['kolab_subscribed_folders'][$i]);
+        }
+
         return self::set_state($folder, false);
     }