diff --git a/IPython/core/interactiveshell.py b/IPython/core/interactiveshell.py
index 7d7d0fe..b78654e 100644
--- a/IPython/core/interactiveshell.py
+++ b/IPython/core/interactiveshell.py
@@ -911,7 +911,8 @@ class InteractiveShell(SingletonConfigurable):
         try:
             main_mod = self._main_mod_cache[filename]
         except KeyError:
-            main_mod = self._main_mod_cache[filename] = types.ModuleType(modname,
+            main_mod = self._main_mod_cache[filename] = types.ModuleType(
+                        py3compat.cast_bytes_py2(modname),
                         doc="Module created for script run in IPython")
         else:
             main_mod.__dict__.clear()
diff --git a/IPython/core/tests/test_interactiveshell.py b/IPython/core/tests/test_interactiveshell.py
index 56211a8..de8d8d7 100644
--- a/IPython/core/tests/test_interactiveshell.py
+++ b/IPython/core/tests/test_interactiveshell.py
@@ -472,6 +472,12 @@ class InteractiveShellTestCase(unittest.TestCase):
         with open(filename, 'r') as f:
             self.assertEqual(f.read(), 'blah')
 
+    def test_new_main_mod(self):
+        # Smoketest to check that this accepts a unicode module name
+        name = u'jiefmw'
+        mod = ip.new_main_mod(u'%s.py' % name, name)
+        self.assertEqual(mod.__name__, name)
+
 class TestSafeExecfileNonAsciiPath(unittest.TestCase):
 
     @onlyif_unicode_paths
diff --git a/IPython/core/ultratb.py b/IPython/core/ultratb.py
index 8d02e8a..5fa0113 100644
--- a/IPython/core/ultratb.py
+++ b/IPython/core/ultratb.py
@@ -805,8 +805,10 @@ class VerboseTB(TBTools):
                     elif token_type == tokenize.NEWLINE:
                         break
 
-            except (IndexError, UnicodeDecodeError):
+            except (IndexError, UnicodeDecodeError, SyntaxError):
                 # signals exit of tokenizer
+                # SyntaxError can occur if the file is not actually Python
+                #  - see gh-6300
                 pass
             except tokenize.TokenError as msg:
                 _m = ("An unexpected error occurred while tokenizing input\n"
diff --git a/IPython/html/base/handlers.py b/IPython/html/base/handlers.py
index 3ca611e..07bc059 100644
--- a/IPython/html/base/handlers.py
+++ b/IPython/html/base/handlers.py
@@ -235,12 +235,13 @@ class IPythonHandler(AuthenticatedHandler):
             raise web.HTTPError(400, u'Invalid JSON in body of request')
         return model
 
-    def get_error_html(self, status_code, **kwargs):
+    def write_error(self, status_code, **kwargs):
         """render custom error pages"""
-        exception = kwargs.get('exception')
+        exc_info = kwargs.get('exc_info')
         message = ''
         status_message = responses.get(status_code, 'Unknown HTTP Error')
-        if exception:
+        if exc_info:
+            exception = exc_info[1]
             # get the custom message, if defined
             try:
                 message = exception.log_message % exception.args
@@ -260,13 +261,16 @@ class IPythonHandler(AuthenticatedHandler):
             exception=exception,
         )
         
+        self.set_header('Content-Type', 'text/html')
         # render the template
         try:
             html = self.render_template('%s.html' % status_code, **ns)
         except TemplateNotFound:
             self.log.debug("No template for %d", status_code)
             html = self.render_template('error.html', **ns)
-        return html
+        
+        self.write(html)
+        
 
 
 class Template404(IPythonHandler):
diff --git a/IPython/html/static/base/js/utils.js b/IPython/html/static/base/js/utils.js
index 5923256..bb903ad 100644
--- a/IPython/html/static/base/js/utils.js
+++ b/IPython/html/static/base/js/utils.js
@@ -514,15 +514,20 @@ define([
         }
     };
     
+    var ajax_error_msg = function (jqXHR) {
+        // Return a JSON error message if there is one,
+        // otherwise the basic HTTP status text.
+        if (jqXHR.responseJSON && jqXHR.responseJSON.message) {
+            return jqXHR.responseJSON.message;
+        } else {
+            return jqXHR.statusText;
+        }
+    }
     var log_ajax_error = function (jqXHR, status, error) {
         // log ajax failures with informative messages
         var msg = "API request failed (" + jqXHR.status + "): ";
         console.log(jqXHR);
-        if (jqXHR.responseJSON && jqXHR.responseJSON.message) {
-            msg += jqXHR.responseJSON.message;
-        } else {
-            msg += jqXHR.statusText;
-        }
+        msg += ajax_error_msg(jqXHR);
         console.log(msg);
     };
 
@@ -547,6 +552,7 @@ define([
         platform: platform,
         is_or_has : is_or_has,
         is_focused : is_focused,
+        ajax_error_msg : ajax_error_msg,
         log_ajax_error : log_ajax_error,
     };
 
diff --git a/IPython/html/static/notebook/js/notebook.js b/IPython/html/static/notebook/js/notebook.js
index 02a4439..e22fd51 100644
--- a/IPython/html/static/notebook/js/notebook.js
+++ b/IPython/html/static/notebook/js/notebook.js
@@ -2286,13 +2286,14 @@ define([
      */
     Notebook.prototype.load_notebook_error = function (xhr, status, error) {
         this.events.trigger('notebook_load_failed.Notebook', [xhr, status, error]);
+        utils.log_ajax_error(xhr, status, error);
         var msg;
         if (xhr.status === 400) {
-            msg = error;
+            msg = escape(utils.ajax_error_msg(xhr));
         } else if (xhr.status === 500) {
             msg = "An unknown error occurred while loading this notebook. " +
             "This version can load notebook formats " +
-            "v" + this.nbformat + " or earlier.";
+            "v" + this.nbformat + " or earlier. See the server log for details.";
         }
         dialog.modal({
             notebook: this,
@@ -2567,10 +2568,10 @@ define([
      * @method delete_checkpoint_error
      * @param {jqXHR} xhr jQuery Ajax object
      * @param {String} status Description of response status
-     * @param {String} error_msg HTTP error message
+     * @param {String} error HTTP error message
      */
-    Notebook.prototype.delete_checkpoint_error = function (xhr, status, error_msg) {
-        this.events.trigger('checkpoint_delete_failed.Notebook');
+    Notebook.prototype.delete_checkpoint_error = function (xhr, status, error) {
+        this.events.trigger('checkpoint_delete_failed.Notebook', [xhr, status, error]);
     };
 
 
diff --git a/IPython/html/static/widgets/js/widget_int.js b/IPython/html/static/widgets/js/widget_int.js
index 09353a4..a92b1d9 100644
--- a/IPython/html/static/widgets/js/widget_int.js
+++ b/IPython/html/static/widgets/js/widget_int.js
@@ -62,22 +62,35 @@ define([
                 // handle in the vertical slider is always 
                 // consistent.
                 var orientation = this.model.get('orientation');
-                var value = this.model.get('min');
+                var min = this.model.get('min');
+                var max = this.model.get('max');
                 if (this.model.get('range')) {
-                    this.$slider.slider('option', 'values', [value, value]);
+                    this.$slider.slider('option', 'values', [min, min]);
                 } else {
-                    this.$slider.slider('option', 'value', value);
+                    this.$slider.slider('option', 'value', min);
                 }
                 this.$slider.slider('option', 'orientation', orientation);
-                value = this.model.get('value');
+                var value = this.model.get('value');
                 if (this.model.get('range')) {
+                	// values for the range case are validated python-side in
+                	// _Bounded{Int,Float}RangeWidget._validate
                     this.$slider.slider('option', 'values', value);
                     this.$readout.text(value.join("-"));
                 } else {
+	                if(value > max) { 
+	                    value = max; 
+	                }
+	                else if(value < min){ 
+	                    value = min; 
+	                }	
                     this.$slider.slider('option', 'value', value);
                     this.$readout.text(value);
                 }
 
+                if(this.model.get('value')!=value) {
+                    this.model.set('value', value, {updated_view: this});
+                    this.touch();
+                }
 
                 // Use the right CSS classes for vertical & horizontal sliders
                 if (orientation=='vertical') {
diff --git a/IPython/html/tree/handlers.py b/IPython/html/tree/handlers.py
index 61d1417..376575d 100644
--- a/IPython/html/tree/handlers.py
+++ b/IPython/html/tree/handlers.py
@@ -80,5 +80,5 @@ default_handlers = [
     (r"/tree%s" % notebook_path_regex, TreeHandler),
     (r"/tree%s" % path_regex, TreeHandler),
     (r"/tree", TreeHandler),
-    (r"", TreeRedirectHandler),
+    (r"/?", TreeRedirectHandler),
     ]
diff --git a/IPython/html/widgets/widget.py b/IPython/html/widgets/widget.py
index be945ca..7ad0ffc 100644
--- a/IPython/html/widgets/widget.py
+++ b/IPython/html/widgets/widget.py
@@ -13,11 +13,12 @@ in the IPython notebook front-end.
 # Imports
 #-----------------------------------------------------------------------------
 from contextlib import contextmanager
+import collections
 
 from IPython.core.getipython import get_ipython
 from IPython.kernel.comm import Comm
 from IPython.config import LoggingConfigurable
-from IPython.utils.traitlets import Unicode, Dict, Instance, Bool, List, Tuple, Int
+from IPython.utils.traitlets import Unicode, Dict, Instance, Bool, List, Tuple, Int, Set
 from IPython.utils.py3compat import string_types
 
 #-----------------------------------------------------------------------------
@@ -98,9 +99,9 @@ class Widget(LoggingConfigurable):
     #-------------------------------------------------------------------------
     _model_name = Unicode('WidgetModel', help="""Name of the backbone model 
         registered in the front-end to create and sync this widget with.""")
-    _view_name = Unicode(help="""Default view registered in the front-end
+    _view_name = Unicode('WidgetView', help="""Default view registered in the front-end
         to use to represent the widget.""", sync=True)
-    _comm = Instance('IPython.kernel.comm.Comm')
+    comm = Instance('IPython.kernel.comm.Comm')
     
     msg_throttle = Int(3, sync=True, help="""Maximum number of msgs the 
         front-end can send before receiving an idle msg from the back-end.""")
@@ -110,7 +111,8 @@ class Widget(LoggingConfigurable):
         return [name for name in self.traits(sync=True)]
     
     _property_lock = Tuple((None, None))
-    
+    _send_state_lock = Int(0)
+    _states_to_send = Set(allow_none=False)
     _display_callbacks = Instance(CallbackDispatcher, ())
     _msg_callbacks = Instance(CallbackDispatcher, ())
     
@@ -119,10 +121,12 @@ class Widget(LoggingConfigurable):
     #-------------------------------------------------------------------------
     def __init__(self, **kwargs):
         """Public constructor"""
+        self._model_id = kwargs.pop('model_id', None)
         super(Widget, self).__init__(**kwargs)
 
         self.on_trait_change(self._handle_property_changed, self.keys)
         Widget._call_widget_constructed(self)
+        self.open()
 
     def __del__(self):
         """Object disposal"""
@@ -132,21 +136,20 @@ class Widget(LoggingConfigurable):
     # Properties
     #-------------------------------------------------------------------------
 
-    @property
-    def comm(self):
-        """Gets the Comm associated with this widget.
-
-        If a Comm doesn't exist yet, a Comm will be created automagically."""
-        if self._comm is None:
-            # Create a comm.
-            self._comm = Comm(target_name=self._model_name)
-            self._comm.on_msg(self._handle_msg)
+    def open(self):
+        """Open a comm to the frontend if one isn't already open."""
+        if self.comm is None:
+            if self._model_id is None:
+                self.comm = Comm(target_name=self._model_name)
+                self._model_id = self.model_id
+            else:
+                self.comm = Comm(target_name=self._model_name, comm_id=self._model_id)
+            self.comm.on_msg(self._handle_msg)
             Widget.widgets[self.model_id] = self
 
             # first update
             self.send_state()
-        return self._comm
-    
+
     @property
     def model_id(self):
         """Gets the model id of this widget.
@@ -164,22 +167,22 @@ class Widget(LoggingConfigurable):
         Closes the underlying comm.
         When the comm is closed, all of the widget views are automatically
         removed from the front-end."""
-        if self._comm is not None:
+        if self.comm is not None:
             Widget.widgets.pop(self.model_id, None)
-            self._comm.close()
-        self._comm = None
+            self.comm.close()
+            self.comm = None
     
     def send_state(self, key=None):
         """Sends the widget state, or a piece of it, to the front-end.
 
         Parameters
         ----------
-        key : unicode (optional)
-            A single property's name to sync with the front-end.
+        key : unicode, or iterable (optional)
+            A single property's name or iterable of property names to sync with the front-end.
         """
         self._send({
             "method" : "update",
-            "state"  : self.get_state()
+            "state"  : self.get_state(key=key)
         })
 
     def get_state(self, key=None):
@@ -187,10 +190,17 @@ class Widget(LoggingConfigurable):
 
         Parameters
         ----------
-        key : unicode (optional)
-            A single property's name to get.
+        key : unicode or iterable (optional)
+            A single property's name or iterable of property names to get.
         """
-        keys = self.keys if key is None else [key]
+        if key is None:
+            keys = self.keys
+        elif isinstance(key, string_types):
+            keys = [key]
+        elif isinstance(key, collections.Iterable):
+            keys = key
+        else:
+            raise ValueError("key must be a string, an iterable of keys, or None")
         state = {}
         for k in keys:
             f = self.trait_metadata(k, 'to_json')
@@ -255,10 +265,29 @@ class Widget(LoggingConfigurable):
         finally:
             self._property_lock = (None, None)
 
+    @contextmanager
+    def hold_sync(self):
+        """Hold syncing any state until the context manager is released"""
+        # We increment a value so that this can be nested.  Syncing will happen when
+        # all levels have been released.
+        self._send_state_lock += 1
+        try:
+            yield
+        finally:
+            self._send_state_lock -=1
+            if self._send_state_lock == 0:
+                self.send_state(self._states_to_send)
+                self._states_to_send.clear()
+
     def _should_send_property(self, key, value):
         """Check the property lock (property_lock)"""
-        return key != self._property_lock[0] or \
-        value != self._property_lock[1]
+        if (key == self._property_lock[0] and value == self._property_lock[1]):
+            return False
+        elif self._send_state_lock > 0:
+            self._states_to_send.add(key)
+            return False
+        else:
+            return True
     
     # Event handlers
     @_show_traceback
@@ -388,7 +417,10 @@ class DOMWidget(Widget):
         selector: unicode (optional, kwarg only)
             JQuery selector to use to apply the CSS key/value.  If no selector 
             is provided, an empty selector is used.  An empty selector makes the 
-            front-end try to apply the css to the top-level element.
+            front-end try to apply the css to a default element.  The default
+            element is an attribute unique to each view, which is a DOM element
+            of the view that should be styled with common CSS (see 
+            `$el_to_style` in the Javascript code).
         """
         if value is None:
             css_dict = dict_or_key
diff --git a/IPython/kernel/comm/comm.py b/IPython/kernel/comm/comm.py
index 502210b..59bee03 100644
--- a/IPython/kernel/comm/comm.py
+++ b/IPython/kernel/comm/comm.py
@@ -23,7 +23,7 @@ class Comm(LoggingConfigurable):
         return self.shell.kernel.iopub_socket
     session = Instance('IPython.kernel.zmq.session.Session')
     def _session_default(self):
-        if self.shell is None:
+        if self.shell is None or not hasattr(self.shell, 'kernel'):
             return
         return self.shell.kernel.session
     
@@ -56,15 +56,16 @@ class Comm(LoggingConfigurable):
     
     def _publish_msg(self, msg_type, data=None, metadata=None, **keys):
         """Helper for sending a comm message on IOPub"""
-        data = {} if data is None else data
-        metadata = {} if metadata is None else metadata
-        content = json_clean(dict(data=data, comm_id=self.comm_id, **keys))
-        self.session.send(self.iopub_socket, msg_type,
-            content,
-            metadata=json_clean(metadata),
-            parent=self.shell.get_parent(),
-            ident=self.topic,
-        )
+        if self.session is not None:
+            data = {} if data is None else data
+            metadata = {} if metadata is None else metadata
+            content = json_clean(dict(data=data, comm_id=self.comm_id, **keys))
+            self.session.send(self.iopub_socket, msg_type,
+                content,
+                metadata=json_clean(metadata),
+                parent=self.shell.get_parent(),
+                ident=self.topic,
+            )
     
     def __del__(self):
         """trigger close on gc"""
@@ -77,7 +78,9 @@ class Comm(LoggingConfigurable):
         if data is None:
             data = self._open_data
         self._closed = False
-        get_ipython().comm_manager.register_comm(self)
+        ip = get_ipython()
+        if hasattr(ip, 'comm_manager'):
+            ip.comm_manager.register_comm(self)
         self._publish_msg('comm_open', data, metadata, target_name=self.target_name)
     
     def close(self, data=None, metadata=None):
@@ -88,7 +91,9 @@ class Comm(LoggingConfigurable):
         if data is None:
             data = self._close_data
         self._publish_msg('comm_close', data, metadata)
-        get_ipython().comm_manager.unregister_comm(self)
+        ip = get_ipython()
+        if hasattr(ip, 'comm_manager'):
+            ip.comm_manager.unregister_comm(self)
         self._closed = True
     
     def send(self, data=None, metadata=None):
diff --git a/IPython/lib/inputhook.py b/IPython/lib/inputhook.py
index a29cec0..13425e1 100644
--- a/IPython/lib/inputhook.py
+++ b/IPython/lib/inputhook.py
@@ -211,7 +211,9 @@ class InputHookManager(object):
             raise ValueError("requires wxPython >= 2.8, but you have %s" % wx.__version__)
         
         from IPython.lib.inputhookwx import inputhook_wx
+        from IPython.external.appnope import nope
         self.set_inputhook(inputhook_wx)
+        nope()
         self._current_gui = GUI_WX
         import wx
         if app is None:
@@ -227,9 +229,11 @@ class InputHookManager(object):
 
         This merely sets PyOS_InputHook to NULL.
         """
+        from IPython.external.appnope import nap
         if GUI_WX in self._apps:
             self._apps[GUI_WX]._in_event_loop = False
         self.clear_inputhook()
+        nap()
 
     def enable_qt4(self, app=None):
         """Enable event loop integration with PyQt4.
@@ -254,8 +258,10 @@ class InputHookManager(object):
             app = QtGui.QApplication(sys.argv)
         """
         from IPython.lib.inputhookqt4 import create_inputhook_qt4
+        from IPython.external.appnope import nope
         app, inputhook_qt4 = create_inputhook_qt4(self, app)
         self.set_inputhook(inputhook_qt4)
+        nope()
 
         self._current_gui = GUI_QT4
         app._in_event_loop = True
@@ -267,9 +273,11 @@ class InputHookManager(object):
 
         This merely sets PyOS_InputHook to NULL.
         """
+        from IPython.external.appnope import nap
         if GUI_QT4 in self._apps:
             self._apps[GUI_QT4]._in_event_loop = False
         self.clear_inputhook()
+        nap()
 
     def enable_gtk(self, app=None):
         """Enable event loop integration with PyGTK.
diff --git a/IPython/nbformat/reader.py b/IPython/nbformat/reader.py
index 78e8a1d..bb94ee4 100644
--- a/IPython/nbformat/reader.py
+++ b/IPython/nbformat/reader.py
@@ -80,6 +80,8 @@ def reads(s, **kwargs):
     nb : NotebookNode
         The notebook that was read.
     """
+    from .current import NBFormatError
+    
     nb_dict = parse_json(s, **kwargs)
     (major, minor) = get_version(nb_dict)
     if major in versions:
diff --git a/IPython/utils/eventful.py b/IPython/utils/eventful.py
new file mode 100644
index 0000000..d02be7b
--- /dev/null
+++ b/IPython/utils/eventful.py
@@ -0,0 +1,299 @@
+"""Contains eventful dict and list implementations."""
+
+# void function used as a callback placeholder.
+def _void(*p, **k): return None
+
+class EventfulDict(dict):
+    """Eventful dictionary.
+
+    This class inherits from the Python intrinsic dictionary class, dict.  It
+    adds events to the get, set, and del actions and optionally allows you to
+    intercept and cancel these actions.  The eventfulness isn't recursive.  In
+    other words, if you add a dict as a child, the events of that dict won't be
+    listened to.  If you find you need something recursive, listen to the `add`
+    and `set` methods, and then cancel `dict` values from being set, and instead
+    set `EventfulDict`s that wrap those `dict`s.  Then you can wire the events
+    to the same handlers if necessary.
+
+    See the on_events, on_add, on_set, and on_del methods for registering 
+    event handlers."""
+
+    def __init__(self, *args, **kwargs):
+        """Public constructor"""
+        self._add_callback = _void
+        self._del_callback = _void
+        self._set_callback = _void
+        dict.__init__(self, *args, **kwargs)
+
+    def on_events(self, add_callback=None, set_callback=None, del_callback=None):
+        """Register callbacks for add, set, and del actions.
+
+        See the doctstrings for on_(add/set/del) for details about each 
+        callback.
+
+        add_callback: [callback = None]
+        set_callback: [callback = None]
+        del_callback: [callback = None]"""
+        self.on_add(add_callback)
+        self.on_set(set_callback)
+        self.on_del(del_callback)
+
+    def on_add(self, callback):
+        """Register a callback for when an item is added to the dict.
+
+        Allows the listener to detect when items are added to the dictionary and
+        optionally cancel the addition.
+
+        callback: callable or None
+            If you want to ignore the addition event, pass None as the callback.
+            The callback should have a signature of callback(key, value).  The
+            callback should return a boolean True if the additon should be
+            canceled, False or None otherwise."""
+        self._add_callback = callback if callable(callback) else _void
+
+    def on_del(self, callback):
+        """Register a callback for when an item is deleted from the dict.
+
+        Allows the listener to detect when items are deleted from the dictionary
+        and optionally cancel the deletion.
+
+        callback: callable or None
+            If you want to ignore the deletion event, pass None as the callback.
+            The callback should have a signature of callback(key).  The
+            callback should return a boolean True if the deletion should be
+            canceled, False or None otherwise."""
+        self._del_callback = callback if callable(callback) else _void
+        
+    def on_set(self, callback):
+        """Register a callback for when an item is changed in the dict.
+
+        Allows the listener to detect when items are changed in the dictionary
+        and optionally cancel the change.
+
+        callback: callable or None
+            If you want to ignore the change event, pass None as the callback.
+            The callback should have a signature of callback(key, value).  The
+            callback should return a boolean True if the change should be
+            canceled, False or None otherwise."""
+        self._set_callback = callback if callable(callback) else _void
+        
+    def pop(self, key):
+        """Returns the value of an item in the dictionary and then deletes the
+        item from the dictionary."""
+        if self._can_del(key):
+            return dict.pop(self, key)
+        else:
+            raise Exception('Cannot `pop`, deletion of key "{}" failed.'.format(key))
+
+    def popitem(self):
+        """Pop the next key/value pair from the dictionary."""
+        key = next(iter(self))
+        return key, self.pop(key)
+
+    def update(self, other_dict):
+        """Copy the key/value pairs from another dictionary into this dictionary,
+        overwriting any conflicting keys in this dictionary."""
+        for (key, value) in other_dict.items():
+            self[key] = value
+            
+    def clear(self):
+        """Clear the dictionary."""
+        for key in list(self.keys()):
+            del self[key]
+
+    def __setitem__(self, key, value):
+        if (key in self and self._can_set(key, value)) or \
+        (key not in self and self._can_add(key, value)):
+            return dict.__setitem__(self, key, value)
+        
+    def __delitem__(self, key):
+        if self._can_del(key):
+            return dict.__delitem__(self, key)
+
+    def _can_add(self, key, value):
+        """Check if the item can be added to the dict."""
+        return not bool(self._add_callback(key, value))
+
+    def _can_del(self, key):
+        """Check if the item can be deleted from the dict."""
+        return not bool(self._del_callback(key))
+
+    def _can_set(self, key, value):
+        """Check if the item can be changed in the dict."""
+        return not bool(self._set_callback(key, value))
+
+
+class EventfulList(list):
+    """Eventful list.
+
+    This class inherits from the Python intrinsic `list` class.  It adds events 
+    that allow you to listen for actions that modify the list.  You can 
+    optionally cancel the actions.
+
+    See the on_del, on_set, on_insert, on_sort, and on_reverse methods for
+    registering an event handler.
+
+    Some of the method docstrings were taken from the Python documentation at
+    https://docs.python.org/2/tutorial/datastructures.html"""
+
+    def __init__(self, *pargs, **kwargs):
+        """Public constructor"""
+        self._insert_callback = _void
+        self._set_callback = _void
+        self._del_callback = _void
+        self._sort_callback = _void
+        self._reverse_callback = _void
+        list.__init__(self, *pargs, **kwargs)
+
+    def on_events(self, insert_callback=None, set_callback=None, 
+        del_callback=None, reverse_callback=None, sort_callback=None):
+        """Register callbacks for add, set, and del actions.
+
+        See the doctstrings for on_(insert/set/del/reverse/sort) for details 
+        about each callback.
+
+        insert_callback: [callback = None]
+        set_callback: [callback = None]
+        del_callback: [callback = None]
+        reverse_callback: [callback = None]
+        sort_callback: [callback = None]"""
+        self.on_insert(insert_callback)
+        self.on_set(set_callback)
+        self.on_del(del_callback)
+        self.on_reverse(reverse_callback)
+        self.on_sort(sort_callback)
+
+    def on_insert(self, callback):
+        """Register a callback for when an item is inserted into the list.
+
+        Allows the listener to detect when items are inserted into the list and
+        optionally cancel the insertion.
+
+        callback: callable or None
+            If you want to ignore the insertion event, pass None as the callback.
+            The callback should have a signature of callback(index, value).  The
+            callback should return a boolean True if the insertion should be
+            canceled, False or None otherwise."""
+        self._insert_callback = callback if callable(callback) else _void
+        
+    def on_del(self, callback):
+        """Register a callback for item deletion.
+
+        Allows the listener to detect when items are deleted from the list and
+        optionally cancel the deletion.
+
+        callback: callable or None
+            If you want to ignore the deletion event, pass None as the callback.
+            The callback should have a signature of callback(index).  The
+            callback should return a boolean True if the deletion should be
+            canceled, False or None otherwise."""
+        self._del_callback = callback if callable(callback) else _void
+        
+    def on_set(self, callback):
+        """Register a callback for items are set.
+
+        Allows the listener to detect when items are set and optionally cancel 
+        the setting.  Note, `set` is also called when one or more items are
+        added to the end of the list.
+
+        callback: callable or None
+            If you want to ignore the set event, pass None as the callback.
+            The callback should have a signature of callback(index, value).  The
+            callback should return a boolean True if the set should be
+            canceled, False or None otherwise."""
+        self._set_callback = callback if callable(callback) else _void
+        
+    def on_reverse(self, callback):
+        """Register a callback for list reversal.
+
+        callback: callable or None
+            If you want to ignore the reverse event, pass None as the callback.
+            The callback should have a signature of callback().  The
+            callback should return a boolean True if the reverse should be
+            canceled, False or None otherwise."""
+        self._reverse_callback = callback if callable(callback) else _void
+        
+    def on_sort(self, callback):
+        """Register a callback for sortting of the list.
+
+        callback: callable or None
+            If you want to ignore the sort event, pass None as the callback.
+            The callback signature should match that of Python list's `.sort` 
+            method or `callback(*pargs, **kwargs)` as a catch all. The callback 
+            should return a boolean True if the reverse should be canceled, 
+            False or None otherwise."""
+        self._sort_callback = callback if callable(callback) else _void
+        
+    def append(self, x):
+        """Add an item to the end of the list."""
+        self[len(self):] = [x]
+
+    def extend(self, L):
+        """Extend the list by appending all the items in the given list."""
+        self[len(self):] = L
+
+    def remove(self, x):
+        """Remove the first item from the list whose value is x. It is an error 
+        if there is no such item."""
+        del self[self.index(x)]
+        
+    def pop(self, i=None):
+        """Remove the item at the given position in the list, and return it. If 
+        no index is specified, a.pop() removes and returns the last item in the 
+        list."""
+        if i is None:
+            i = len(self) - 1
+        val = self[i]
+        del self[i]
+        return val
+
+    def reverse(self):
+        """Reverse the elements of the list, in place."""
+        if self._can_reverse():
+            list.reverse(self)
+    
+    def insert(self, index, value):
+        """Insert an item at a given position. The first argument is the index 
+        of the element before which to insert, so a.insert(0, x) inserts at the 
+        front of the list, and a.insert(len(a), x) is equivalent to 
+        a.append(x)."""
+        if self._can_insert(index, value):
+            list.insert(self, index, value)
+
+    def sort(self, *pargs, **kwargs):
+        """Sort the items of the list in place (the arguments can be used for 
+        sort customization, see Python's sorted() for their explanation)."""
+        if self._can_sort(*pargs, **kwargs):
+            list.sort(self, *pargs, **kwargs)
+
+    def __delitem__(self, index):
+        if self._can_del(index):
+            list.__delitem__(self, index)
+
+    def __setitem__(self, index, value):
+        if self._can_set(index, value):
+            list.__setitem__(self, index, value)
+
+    def __setslice__(self, start, end, value):
+        if self._can_set(slice(start, end), value):
+            list.__setslice__(self, start, end, value)
+    
+    def _can_insert(self, index, value):
+        """Check if the item can be inserted."""
+        return not bool(self._insert_callback(index, value))
+
+    def _can_del(self, index):
+        """Check if the item can be deleted."""
+        return not bool(self._del_callback(index))
+
+    def _can_set(self, index, value):
+        """Check if the item can be set."""
+        return not bool(self._set_callback(index, value))
+
+    def _can_reverse(self):
+        """Check if the list can be reversed."""
+        return not bool(self._reverse_callback())
+
+    def _can_sort(self, *pargs, **kwargs):
+        """Check if the list can be sorted."""
+        return not bool(self._sort_callback(*pargs, **kwargs))
diff --git a/IPython/utils/tests/test_traitlets.py b/IPython/utils/tests/test_traitlets.py
index 8992345..fcb3ca2 100644
--- a/IPython/utils/tests/test_traitlets.py
+++ b/IPython/utils/tests/test_traitlets.py
@@ -19,7 +19,8 @@ from IPython.utils.traitlets import (
     HasTraits, MetaHasTraits, TraitType, Any, CBytes, Dict,
     Int, Long, Integer, Float, Complex, Bytes, Unicode, TraitError,
     Undefined, Type, This, Instance, TCPAddress, List, Tuple,
-    ObjectName, DottedObjectName, CRegExp, link
+    ObjectName, DottedObjectName, CRegExp, link, directional_link,
+    EventfulList, EventfulDict
 )
 from IPython.utils import py3compat
 from IPython.testing.decorators import skipif
@@ -1034,7 +1035,7 @@ class TestCRegExp(TraitTestBase):
 
     _default_value = re.compile(r'')
     _good_values = [r'\d+', re.compile(r'\d+')]
-    _bad_values = [r'(', None, ()]
+    _bad_values = ['(', None, ()]
 
 class DictTrait(HasTraits):
     value = Dict()
@@ -1147,6 +1148,71 @@ class TestLink(TestCase):
         self.assertEqual(''.join(callback_count), 'ab')
         del callback_count[:]
 
+class TestDirectionalLink(TestCase):
+    def test_connect_same(self):
+        """Verify two traitlets of the same type can be linked together using directional_link."""
+
+        # Create two simple classes with Int traitlets.
+        class A(HasTraits):
+            value = Int()
+        a = A(value=9)
+        b = A(value=8)
+
+        # Conenct the two classes.
+        c = directional_link((a, 'value'), (b, 'value'))
+
+        # Make sure the values are the same at the point of linking.
+        self.assertEqual(a.value, b.value)
+
+        # Change one the value of the source and check that it synchronizes the target.
+        a.value = 5
+        self.assertEqual(b.value, 5)
+        # Change one the value of the target and check that it has no impact on the source
+        b.value = 6
+        self.assertEqual(a.value, 5)
+
+    def test_link_different(self):
+        """Verify two traitlets of different types can be linked together using link."""
+
+        # Create two simple classes with Int traitlets.
+        class A(HasTraits):
+            value = Int()
+        class B(HasTraits):
+            count = Int()
+        a = A(value=9)
+        b = B(count=8)
+
+        # Conenct the two classes.
+        c = directional_link((a, 'value'), (b, 'count'))
+
+        # Make sure the values are the same at the point of linking.
+        self.assertEqual(a.value, b.count)
+
+        # Change one the value of the source and check that it synchronizes the target.
+        a.value = 5
+        self.assertEqual(b.count, 5)
+        # Change one the value of the target and check that it has no impact on the source
+        b.value = 6
+        self.assertEqual(a.value, 5)
+
+    def test_unlink(self):
+        """Verify two linked traitlets can be unlinked."""
+
+        # Create two simple classes with Int traitlets.
+        class A(HasTraits):
+            value = Int()
+        a = A(value=9)
+        b = A(value=8)
+
+        # Connect the two classes.
+        c = directional_link((a, 'value'), (b, 'value'))
+        a.value = 4
+        c.unlink()
+
+        # Change one of the values to make sure they don't stay in sync.
+        a.value = 5
+        self.assertNotEqual(a.value, b.value)
+
 class Pickleable(HasTraits):
     i = Int()
     j = Int()
@@ -1171,4 +1237,65 @@ def test_pickle_hastraits():
         c2 = pickle.loads(p)
         nt.assert_equal(c2.i, c.i)
         nt.assert_equal(c2.j, c.j)
-    
+
+class TestEventful(TestCase):
+
+    def test_list(self):
+        """Does the EventfulList work?"""
+        event_cache = []
+
+        class A(HasTraits):
+            x = EventfulList([c for c in 'abc'])
+        a = A()
+        a.x.on_events(lambda i, x: event_cache.append('insert'), \
+            lambda i, x: event_cache.append('set'), \
+            lambda i: event_cache.append('del'), \
+            lambda: event_cache.append('reverse'), \
+            lambda *p, **k: event_cache.append('sort'))
+
+        a.x.remove('c')
+        # ab
+        a.x.insert(0, 'z')
+        # zab
+        del a.x[1]
+        # zb
+        a.x.reverse()
+        # bz 
+        a.x[1] = 'o'
+        # bo
+        a.x.append('a')
+        # boa
+        a.x.sort()
+        # abo
+
+        # Were the correct events captured?
+        self.assertEqual(event_cache, ['del', 'insert', 'del', 'reverse', 'set', 'set', 'sort'])
+
+        # Is the output correct?
+        self.assertEqual(a.x, [c for c in 'abo'])
+
+    def test_dict(self):
+        """Does the EventfulDict work?"""
+        event_cache = []
+
+        class A(HasTraits):
+            x = EventfulDict({c: c for c in 'abc'})
+        a = A()
+        a.x.on_events(lambda k, v: event_cache.append('add'), \
+            lambda k, v: event_cache.append('set'), \
+            lambda k: event_cache.append('del'))
+
+        del a.x['c']
+        # ab
+        a.x['z'] = 1
+        # abz
+        a.x['z'] = 'z'
+        # abz
+        a.x.pop('a')
+        # bz 
+
+        # Were the correct events captured?
+        self.assertEqual(event_cache, ['del', 'add', 'set', 'del'])
+
+        # Is the output correct?
+        self.assertEqual(a.x, {c: c for c in 'bz'})
diff --git a/IPython/utils/traitlets.py b/IPython/utils/traitlets.py
index 1a68b04..7b65196 100644
--- a/IPython/utils/traitlets.py
+++ b/IPython/utils/traitlets.py
@@ -54,6 +54,7 @@ except:
 
 from .importstring import import_item
 from IPython.utils import py3compat
+from IPython.utils import eventful
 from IPython.utils.py3compat import iteritems
 from IPython.testing.skipdoctest import skip_doctest
 
@@ -226,6 +227,61 @@ class link(object):
             (obj,attr) = key
             obj.on_trait_change(callback, attr, remove=True)
 
+@skip_doctest
+class directional_link(object):
+    """Link the trait of a source object with traits of target objects.
+
+    Parameters
+    ----------
+    source : pair of object, name
+    targets : pairs of objects/attributes
+
+    Examples
+    --------
+
+    >>> c = directional_link((src, 'value'), (tgt1, 'value'), (tgt2, 'value'))
+    >>> src.value = 5  # updates target objects
+    >>> tgt1.value = 6 # does not update other objects
+    """
+    updating = False
+
+    def __init__(self, source, *targets):
+        self.source = source
+        self.targets = targets
+
+        # Update current value
+        src_attr_value = getattr(source[0], source[1])
+        for obj, attr in targets:
+            if getattr(obj, attr) != src_attr_value:
+                setattr(obj, attr, src_attr_value)
+
+        # Wire
+        self.source[0].on_trait_change(self._update, self.source[1])
+
+    @contextlib.contextmanager
+    def _busy_updating(self):
+        self.updating = True
+        try:
+            yield
+        finally:
+            self.updating = False
+
+    def _update(self, name, old, new):
+        if self.updating:
+            return
+        with self._busy_updating():
+            for obj, attr in self.targets:
+                setattr(obj, attr, new)
+
+    def unlink(self):
+        self.source[0].on_trait_change(self._update, self.source[1], remove=True)
+        self.source = None
+        self.targets = []
+
+def dlink(source, *targets):
+    """Shorter helper function returning a directional_link object"""
+    return directional_link(source, *targets)
+
 #-----------------------------------------------------------------------------
 # Base TraitType for all traits
 #-----------------------------------------------------------------------------
@@ -1490,6 +1546,49 @@ class Dict(Instance):
         super(Dict,self).__init__(klass=dict, args=args,
                                   allow_none=allow_none, **metadata)
 
+
+class EventfulDict(Instance):
+    """An instance of an EventfulDict."""
+
+    def __init__(self, default_value=None, allow_none=True, **metadata):
+        """Create a EventfulDict trait type from a dict.
+
+        The default value is created by doing 
+        ``eventful.EvenfulDict(default_value)``, which creates a copy of the 
+        ``default_value``.
+        """
+        if default_value is None:
+            args = ((),)
+        elif isinstance(default_value, dict):
+            args = (default_value,)
+        elif isinstance(default_value, SequenceTypes):
+            args = (default_value,)
+        else:
+            raise TypeError('default value of EventfulDict was %s' % default_value)
+
+        super(EventfulDict, self).__init__(klass=eventful.EventfulDict, args=args,
+                                  allow_none=allow_none, **metadata)
+
+
+class EventfulList(Instance):
+    """An instance of an EventfulList."""
+
+    def __init__(self, default_value=None, allow_none=True, **metadata):
+        """Create a EventfulList trait type from a dict.
+
+        The default value is created by doing 
+        ``eventful.EvenfulList(default_value)``, which creates a copy of the 
+        ``default_value``.
+        """
+        if default_value is None:
+            args = ((),)
+        else:
+            args = (default_value,)
+
+        super(EventfulList, self).__init__(klass=eventful.EventfulList, args=args,
+                                  allow_none=allow_none, **metadata)
+
+
 class TCPAddress(TraitType):
     """A trait for an (ip, port) tuple.
 
diff --git a/docs/source/config/extensions/rmagic.rst b/docs/source/config/extensions/rmagic.rst
index 77104f2..cc16592 100644
--- a/docs/source/config/extensions/rmagic.rst
+++ b/docs/source/config/extensions/rmagic.rst
@@ -7,6 +7,6 @@ rmagic
 .. note::
 
    The rmagic extension has been moved to `rpy2 <http://rpy.sourceforge.net/rpy2.html>`_
-   as :mod:`rpy2.interactive.ipython`.
+   as :mod:`rpy2.ipython`.
 
 .. automodule:: IPython.extensions.rmagic
diff --git a/docs/source/development/wrapperkernels.rst b/docs/source/development/wrapperkernels.rst
index e345333..a8817a0 100644
--- a/docs/source/development/wrapperkernels.rst
+++ b/docs/source/development/wrapperkernels.rst
@@ -73,7 +73,7 @@ Example
         language_version = '0.1'
         banner = "Echo kernel - as useful as a parrot"
 
-        def do_execute(self, code, silent, store_history=True, user_experssions=None,
+        def do_execute(self, code, silent, store_history=True, user_expressions=None,
                        allow_stdin=False):
             if not silent:
                 stream_content = {'name': 'stdout', 'data':code}
diff --git a/git-hooks/post-checkout b/git-hooks/post-checkout
index 5bb02c7..a8b1206 100755
--- a/git-hooks/post-checkout
+++ b/git-hooks/post-checkout
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 git submodule init
 git submodule update
diff --git a/tools/build_release b/tools/build_release
index 3f2cfe6..c19870e 100755
--- a/tools/build_release
+++ b/tools/build_release
@@ -3,6 +3,7 @@
 """
 
 import os
+from shutil import rmtree
 
 from toollib import *
 
@@ -20,7 +21,7 @@ compile_tree()
 for d in ['build', 'dist', pjoin('docs', 'build'), pjoin('docs', 'dist'),
           pjoin('docs', 'source', 'api', 'generated')]:
     if os.path.isdir(d):
-        remove_tree(d)
+        rmtree(d)
 
 # Build source and binary distros
 sh(sdists)
diff --git a/tools/release b/tools/release
index 6b25012..56a82a8 100755
--- a/tools/release
+++ b/tools/release
@@ -56,7 +56,7 @@ sh('./setup.py register')
 # Upload all files
 sh(sdists + ' upload')
 for py in ('2.7', '3.4'):
-    sh('python%s setupegg.py bdist_wheel' % py)
+    sh('python%s setupegg.py bdist_wheel upload' % py)
 
 cd(distdir)
 print( 'Uploading distribution files...')
diff --git a/tools/toollib.py b/tools/toollib.py
index 6804674..a448d57 100644
--- a/tools/toollib.py
+++ b/tools/toollib.py
@@ -42,7 +42,7 @@ def get_ipdir():
     try:
         ipdir = sys.argv[1]
     except IndexError:
-        ipdir = '..'
+        ipdir = pjoin(os.path.dirname(__file__), os.pardir)
 
     ipdir = os.path.abspath(ipdir)