diff --git a/modoboa/extensions/admin/static/admin/js/admin.js b/modoboa/extensions/admin/static/admin/js/admin.js
index 0ed43c300..04a89070e 100644
--- a/modoboa/extensions/admin/static/admin/js/admin.js
+++ b/modoboa/extensions/admin/static/admin/js/admin.js
@@ -25,7 +25,7 @@ Admin.prototype = {
             $(this).val("");
         }).blur($.proxy(function(e) {
             var $this = $(e.target);
-            if ($this.val() == "") {
+            if ($this.val() === "") {
                 if (this.navobj.getparam("searchquery")) {
                     $this.val(this.navobj.getparam("searchquery"));
                 } else {
@@ -33,7 +33,7 @@ Admin.prototype = {
                 }
             }
         }, this));
-        if (this.navobj.getparam("searchquery") != undefined) {
+        if (this.navobj.getparam("searchquery") !== undefined) {
             $("#searchquery").val(this.navobj.getparam("searchquery"));
         }
 
@@ -52,14 +52,14 @@ Admin.prototype = {
 
     register_tag_handler: function(name, handler) {
         this.tag_handlers[name] = handler;
-        if (this.navobj.getparam(name + "filter") != undefined) {
+        if (this.navobj.getparam(name + "filter") !== undefined) {
             var text = this.navobj.getparam(name + "filter");
             $("#searchform").parent().after(this.make_tag(text, name));
         }
     },
 
     generic_tag_handler: function(tag, $link) {
-        if (this.navobj.getparam(tag + "filter") == undefined && $link.hasClass(tag)) {
+        if (this.navobj.getparam(tag + "filter") === undefined && $link.hasClass(tag)) {
             var text = $link.attr("name");
             this.navobj.setparam(tag + "filter", text).update();
             $("#searchform").parent().after(this.make_tag(text, tag));
@@ -101,7 +101,7 @@ Admin.prototype = {
     do_search: function(e) {
         e.preventDefault();
         var squery = $("#searchquery").val();
-        if (squery != "") {
+        if (squery !== "") {
             this.navobj.setparam("searchquery", squery);
         } else {
             this.navobj.delparam("searchquery");
@@ -112,7 +112,7 @@ Admin.prototype = {
     importform_cb: function() {
         $(".submit").one('click', function(e) {
             e.preventDefault();
-            if ($("#id_sourcefile").val() == "") {
+            if ($("#id_sourcefile").val() === "") {
                 return;
             }
             $("#import_status").css("display", "block");
@@ -305,13 +305,13 @@ Identities.prototype = {
     },
 
     grp_tag_handler: function(tag, $link) {
-        if (this.navobj.getparam(tag + "filter") == undefined && $link.hasClass(tag)) {
+        if (this.navobj.getparam(tag + "filter") === undefined && $link.hasClass(tag)) {
             var text = $link.attr("name");
             this.navobj
                 .setparam("idtfilter", "account")
                 .setparam(tag + "filter", text)
                 .update();
-            if ($("a[name=idt]").length == 0) {
+            if ($("a[name=idt]").length === 0) {
                 $("#searchform").parent().after(this.make_tag("account", "idt"));
             }
             $("#searchform").parent().after(this.make_tag(text, tag));
@@ -341,13 +341,13 @@ Identities.prototype = {
             var $this = $(e.target);
             var value = $this.val();
 
-            if (value == "SimpleUsers" || value == "") {
+            if (value == "SimpleUsers" || value === "") {
                 this.simpleuser_mode();
             } else {
                 this.normal_mode();
             }
         }, this));
-        if (notrigger != undefined && notrigger) {
+        if (notrigger !== undefined && notrigger) {
             return;
         }
         $("#id_role").trigger("change");
@@ -382,7 +382,7 @@ Identities.prototype = {
 
     mailform_prefill: function() {
         var $role = $("#id_role");
-        if (!$role.length || $role.val() == "" || $role.val() == "SimpleUsers") {
+        if (!$role.length || $role.val() === "" || $role.val() == "SimpleUsers") {
             $("#id_email").val($("#id_username").val());
         }
     },
diff --git a/modoboa/extensions/radicale/app_settings.py b/modoboa/extensions/radicale/app_settings.py
index 82e5783b9..f2ad2b9c4 100644
--- a/modoboa/extensions/radicale/app_settings.py
+++ b/modoboa/extensions/radicale/app_settings.py
@@ -1,8 +1,13 @@
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import ugettext_lazy
 from django import forms
-from modoboa.lib.parameters import AdminParametersForm, UserParametersForm
-from modoboa.lib.formutils import SeparatorField, YesNoField, InlineRadioSelect
+from modoboa.lib.parameters import AdminParametersForm
 
 
 class ParametersForm(AdminParametersForm):
     app = "radicale"
+
+    rights_file_path = forms.CharField(
+        label=ugettext_lazy("Radicale rights file path"),
+        initial="/etc/radicale/rights",
+        help_text=ugettext_lazy("Path to file that contains rights definition")
+    )
diff --git a/modoboa/extensions/radicale/management/__init__.py b/modoboa/extensions/radicale/management/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/modoboa/extensions/radicale/management/commands/__init__.py b/modoboa/extensions/radicale/management/commands/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/modoboa/extensions/radicale/management/commands/generate_rights.py b/modoboa/extensions/radicale/management/commands/generate_rights.py
new file mode 100644
index 000000000..bf95cdf0f
--- /dev/null
+++ b/modoboa/extensions/radicale/management/commands/generate_rights.py
@@ -0,0 +1,10 @@
+from django.core.management.base import BaseCommand, CommandError
+
+
+class Command(BaseCommand):
+    help = ""
+
+    def handle(self, *args, **options):
+        """Command entry point.
+        """
+        pass
diff --git a/modoboa/extensions/radicale/models.py b/modoboa/extensions/radicale/models.py
index 389d59a48..11d94f259 100644
--- a/modoboa/extensions/radicale/models.py
+++ b/modoboa/extensions/radicale/models.py
@@ -112,6 +112,8 @@ class SharedCalendar(Calendar):
 
 @python_2_unicode_compatible
 class AccessRule(models.Model):
+    """Access rules to user calendars
+    """
     mailbox = models.ForeignKey("admin.Mailbox")
     read = models.BooleanField(default=False)
     write = models.BooleanField(default=False)
diff --git a/modoboa/extensions/radicale/static/radicale/js/radicale.js b/modoboa/extensions/radicale/static/radicale/js/radicale.js
index 17a17dea8..4b4070751 100644
--- a/modoboa/extensions/radicale/static/radicale/js/radicale.js
+++ b/modoboa/extensions/radicale/static/radicale/js/radicale.js
@@ -47,8 +47,27 @@ Radicale.prototype = {
         });
     },
 
+    /**
+     * Retrieve a list of username from the server.
+     */
+    get_username_list: function() {
+        var result;
+
+        $.ajax({
+            url: this.options.username_list_url,
+            dataType: "json",
+            async: false
+        }).done(function(data) {
+            result = data;
+        });
+        return result;
+    },
+
     edit_calendar_cb: function() {
         $("#original_row").dynamicrule();
+        $("#id_username").autocompleter({
+            choices: $.proxy(this.get_username_list, this)
+        });
         $('.submit').on('click', $.proxy(function(e) {
             simple_ajax_form_post(e, {
                 formid: "ucal_form",
@@ -58,10 +77,10 @@ Radicale.prototype = {
         }, this));
     },
 
-    add_shared_calendar_cb: function() {
+    shared_calendar_cb: function() {
         $('.submit').on('click', $.proxy(function(e) {
             simple_ajax_form_post(e, {
-                formid: "newsharedcal_form",
+                formid: "sharedcal_form",
                 reload_on_success: false,
                 success_cb: $.proxy(this.reload_listing, this)
             });
diff --git a/modoboa/extensions/radicale/templates/radicale/calendars.html b/modoboa/extensions/radicale/templates/radicale/calendars.html
index bbdb06597..e554951cc 100644
--- a/modoboa/extensions/radicale/templates/radicale/calendars.html
+++ b/modoboa/extensions/radicale/templates/radicale/calendars.html
@@ -5,11 +5,14 @@
 <script type="text/javascript" src="{{ STATIC_URL }}js/history.js"></script>
 <script type="text/javascript" src="{{ STATIC_URL }}js/creation_wizard.js"></script>
 <script type="text/javascript" src="{{ STATIC_URL }}js/listing.js"></script>
+<script type="text/javascript" src="{{ STATIC_URL }}js/autocompleter.js"></script>
 <script type="text/javascript" src="{{ STATIC_URL }}radicale/js/jquery.dynamicrule.js"></script>
 <script type="text/javascript" src="{{ STATIC_URL }}radicale/js/radicale.js"></script>
 <script type="text/javascript">
 $(document).ready(function() {
-    radicale = new Radicale({});
+    radicale = new Radicale({
+        "username_list_url": "{% url 'usernames' %}"
+    });
 });
 </script>
 {% endblock %}
diff --git a/modoboa/extensions/radicale/templatetags/radicale_tags.py b/modoboa/extensions/radicale/templatetags/radicale_tags.py
index 4bd5810c5..1fd7de54b 100644
--- a/modoboa/extensions/radicale/templatetags/radicale_tags.py
+++ b/modoboa/extensions/radicale/templatetags/radicale_tags.py
@@ -33,7 +33,7 @@ def radicale_left_menu(user):
              "label": _("Add shared calendar"),
              "img": "icon-plus",
              "modal": True,
-             "modalcb": "radicale.add_shared_calendar_cb",
+             "modalcb": "radicale.shared_calendar_cb",
              "url": reverse("new_shared_calendar")},
         ]
     return render_to_string('common/menulist.html', {
@@ -56,6 +56,7 @@ def calendar_modify_link(calendar):
         linkdef["url"] = reverse(
             "shared_calendar", args=[calendar.pk]
         )
+        linkdef["modalcb"] = "radicale.shared_calendar_cb"
     return render_link(linkdef)
 
 
diff --git a/modoboa/extensions/radicale/urls.py b/modoboa/extensions/radicale/urls.py
index e7855a63f..03a5d40de 100644
--- a/modoboa/extensions/radicale/urls.py
+++ b/modoboa/extensions/radicale/urls.py
@@ -10,4 +10,5 @@ urlpatterns = patterns(
         name='new_shared_calendar'),
     url(r'^sharedcalendar/(?P<pk>\d+)/$', 'shared_calendar',
         name='shared_calendar'),
+    url(r'^usernames/$', 'username_list', name='usernames'),
 )
diff --git a/modoboa/extensions/radicale/views.py b/modoboa/extensions/radicale/views.py
index de32cd586..b9bbd63ad 100644
--- a/modoboa/extensions/radicale/views.py
+++ b/modoboa/extensions/radicale/views.py
@@ -6,7 +6,7 @@ from itertools import chain
 from django.shortcuts import render
 from django.core.urlresolvers import reverse
 from django.contrib.auth.decorators import (
-    login_required
+    login_required, permission_required, user_passes_test
 )
 from django.utils.translation import ugettext as _
 
@@ -29,10 +29,13 @@ def index(request):
 
 @login_required
 def calendars(request, tplname="radicale/calendar_list.html"):
+    """Display calendars list.
+
+    The content depends on current user's role.
+    """
     if request.user.group == "SimpleUsers":
-        cals = UserCalendar.objects.filter(
-            mailbox=request.user.mailbox_set.all()[0]
-        )
+        mbox = request.user.mailbox_set.all()[0]
+        cals = UserCalendar.objects.filter(mailbox=mbox).select_related().all()
     else:
         cals = chain(
             UserCalendar.objects.get_for_admin(request.user),
@@ -47,6 +50,8 @@ def calendars(request, tplname="radicale/calendar_list.html"):
 
 @login_required
 def new_user_calendar(request):
+    """Calendar creation view.
+    """
     return UserCalendarWizard(request).process()
 
 
@@ -67,7 +72,10 @@ def user_calendar(request, pk):
 
 
 @login_required
+@permission_required("radicale.add_sharedcalendar")
 def new_shared_calendar(request):
+    """Shared calendar creation view.
+    """
     if request.method == "POST":
         form = SharedCalendarForm(request.POST)
         if form.is_valid():
@@ -79,7 +87,7 @@ def new_shared_calendar(request):
     form = SharedCalendarForm()
     return render(request, "common/generic_modal_form.html", {
         "form": form,
-        "formid": "newsharedcal_form",
+        "formid": "sharedcal_form",
         "title": _("New shared calendar"),
         "action": reverse("new_shared_calendar"),
         "action_classes": "submit",
@@ -88,6 +96,11 @@ def new_shared_calendar(request):
 
 
 @login_required
+@permission_required("radicale.add_sharedcalendar")
+@user_passes_test(
+    lambda u: u.has_perm("radicale.change_sharedcalendar")
+              or u.has_perm("radicale.delete_sharedcalendar")
+)
 def shared_calendar(request, pk):
     """
     """
@@ -100,4 +113,32 @@ def shared_calendar(request, pk):
     if request.method == "DELETE":
         scal.delete()
         return render_to_json_response(_("Calendar removed"))
-  
+    if request.method == "POST":
+        form = SharedCalendarForm(request.POST, instance=scal)
+        if form.is_valid():
+            form.save()
+            return render_to_json_response(_("Calendar updated"))
+        return render_to_json_response(
+            {"form_errors": form.errors}, status=400
+        )
+    form = SharedCalendarForm(instance=scal)
+    return render(request, "common/generic_modal_form.html", {
+        "form": form,
+        "formid": "sharedcal_form",
+        "title": scal.name,
+        "action": reverse("shared_calendar", args=[scal.pk]),
+        "action_classes": "submit",
+        "action_label": _("Submit")
+    })
+
+
+@login_required
+def username_list(request):
+    """Get the list of username the current user can see.
+    """
+    from modoboa.extensions.admin.models import Mailbox
+
+    result = []
+    for mb in Mailbox.objects.prefetch_related("user").all():
+        result.append(mb.user.username)
+    return render_to_json_response(result)
diff --git a/modoboa/static/js/autocompleter.js b/modoboa/static/js/autocompleter.js
index c726ba256..0b826cbe8 100644
--- a/modoboa/static/js/autocompleter.js
+++ b/modoboa/static/js/autocompleter.js
@@ -1,4 +1,6 @@
 (function($) {
+    "use strict";
+
     var Autocompleter = function(element, options) {
         this.initialize(element, options);
     };
@@ -9,13 +11,10 @@
         initialize: function(element, options) {
             this.$element = $(element);
             this.options = $.extend({}, $.fn.autocompleter.defaults, options);
-            this.choices = {
-                value: null
-            };
             if (typeof this.options.choices === "function") {
-                this.options.choices(this.choices);
+                this.choices = this.options.choices();
             } else {
-                this.choices.value = this.options.choices();
+                this.choices = this.options.choices;
             }
             this.$menu =
                 $('<ul class="dropdown-menu autocompleter" data-toggle="dropdown" />');
@@ -54,10 +53,11 @@
             var exp = new RegExp("^" + pattern);
 
             this.$menu.empty();
-            $.each(this.choices.value, $.proxy(function(index, value) {
+            $.each(this.choices, $.proxy(function(index, value) {
                 if (exp.test(value)) {
-                    this.$menu.append($('<li><a href="#" name="' + value
-                        + '">' + value + '</a></li>'));
+                    this.$menu.append(
+                        $('<li><a href="#" name="' + value + '">' + value + '</a></li>')
+                    );
                 }
             }, this));
 
@@ -71,6 +71,7 @@
                 'z-index': 1051
             });
             if (this.$menu.children().length) {
+                this.$menu.children().first().addClass("active");
                 this.$menu.show();
             } else {
                 this.$menu.hide();
@@ -84,7 +85,7 @@
         select_entry: function(evt) {
             if (this.$menu.is(":visible")) {
                 var $link;
-                if (evt != undefined) {
+                if (evt !== undefined) {
                     evt.preventDefault();
                     $link = $(evt.target);
                 } else {
@@ -92,7 +93,7 @@
                 }
                 var curvalue = this.$element.val();
 
-                if (curvalue == undefined || curvalue == "") {
+                if (curvalue === undefined || curvalue === "") {
                     if (this.options.empty_choice) {
                         this.options.empty_choice();
                     }
@@ -111,19 +112,18 @@
         },
 
         activate_next: function() {
-            var active = this.$menu.find('.active').removeClass('active')
-                , next = active.next();
+            var active = this.$menu.find('.active').removeClass('active'),
+                next = active.next();
 
             if (!next.length) {
                 next = $(this.$menu.find('li').first());
             }
-
             next.addClass('active');
         },
 
         activate_prev: function() {
-            var active = this.$menu.find('.active').removeClass('active')
-                , prev = active.prev();
+            var active = this.$menu.find('.active').removeClass('active'),
+                prev = active.prev();
 
             if (!prev.length) {
                 prev = this.$menu.find('li').last();
@@ -170,7 +170,7 @@
 
             default:
                 this.check_user_input();
-            };
+            }
         }
     };
 
@@ -194,4 +194,4 @@
         'empty_choice' : null
     };
 
-})(jQuery);
\ No newline at end of file
+})(jQuery);