diff --git a/docs/api-guide/generic-views.md b/docs/api-guide/generic-views.md
index 931cae542..7185b6b68 100755
--- a/docs/api-guide/generic-views.md
+++ b/docs/api-guide/generic-views.md
@@ -73,7 +73,7 @@ The following attributes control the basic view behavior.
 
 **Pagination**:
 
-The following attibutes are used to control pagination when used with list views.
+The following attributes are used to control pagination when used with list views.
 
 * `paginate_by` - The size of pages to use with paginated data.  If set to `None` then pagination is turned off.  If unset this uses the same value as the `PAGINATE_BY` setting, which defaults to `None`.
 * `paginate_by_param` - The name of a query parameter, which can be used by the client to override the default page size to use for pagination.  If unset this uses the same value as the `PAGINATE_BY_PARAM` setting, which defaults to `None`.
@@ -135,7 +135,7 @@ For example:
 
 #### `get_paginate_by(self)`
 
-Returns the page size to use with pagination.  By default this uses the `paginate_by` attribute, and may be overridden by the cient if the `paginate_by_param` attribute is set.
+Returns the page size to use with pagination.  By default this uses the `paginate_by` attribute, and may be overridden by the client if the `paginate_by_param` attribute is set.
 
 You may want to override this method to provide more complex behavior such as modifying page sizes based on the media type of the response.
 
diff --git a/docs/api-guide/pagination.md b/docs/api-guide/pagination.md
index ca0174b76..0829589f8 100644
--- a/docs/api-guide/pagination.md
+++ b/docs/api-guide/pagination.md
@@ -85,11 +85,12 @@ We could now use our pagination serializer in a view like this.
 
 The generic class based views `ListAPIView` and `ListCreateAPIView` provide pagination of the returned querysets by default.  You can customise this behaviour by altering the pagination style, by modifying the default number of results, by allowing clients to override the page size using a query parameter, or by turning pagination off completely.
 
-The default pagination style may be set globally, using the `DEFAULT_PAGINATION_SERIALIZER_CLASS`, `PAGINATE_BY` and `PAGINATE_BY_PARAM` settings.  For example.
+The default pagination style may be set globally, using the `DEFAULT_PAGINATION_SERIALIZER_CLASS`, `PAGINATE_BY`, `PAGINATE_BY_PARAM`, and `MAX_PAGINATE_BY` settings.  For example.
 
     REST_FRAMEWORK = {
-        'PAGINATE_BY': 10,
-        'PAGINATE_BY_PARAM': 'page_size' 
+        'PAGINATE_BY': 10,                 # Default to 10
+        'PAGINATE_BY_PARAM': 'page_size',  # Allow client to override, using `?page_size=xxx`.
+        'MAX_PAGINATE_BY': 100             # Maximum limit allowed when using `?page_size=xxx`.
     }
 
 You can also set the pagination style on a per-view basis, using the `ListAPIView` generic class-based view.
@@ -99,6 +100,7 @@ You can also set the pagination style on a per-view basis, using the `ListAPIVie
         serializer_class = ExampleModelSerializer
         paginate_by = 10
         paginate_by_param = 'page_size'
+        max_paginate_by = 100
 
 Note that using a `paginate_by` value of `None` will turn off pagination for the view.
 
diff --git a/docs/api-guide/parsers.md b/docs/api-guide/parsers.md
index d3c42b1c2..1030fcb65 100644
--- a/docs/api-guide/parsers.md
+++ b/docs/api-guide/parsers.md
@@ -34,7 +34,7 @@ The default set of parsers may be set globally, using the `DEFAULT_PARSER_CLASSE
         )
     }
 
-You can also set the renderers used for an individual view, or viewset,
+You can also set the parsers used for an individual view, or viewset,
 using the `APIView` class based views.
 
 	from rest_framework.parsers import YAMLParser
diff --git a/docs/api-guide/permissions.md b/docs/api-guide/permissions.md
index 12aa4c18b..a7bf15556 100644
--- a/docs/api-guide/permissions.md
+++ b/docs/api-guide/permissions.md
@@ -212,6 +212,10 @@ The following third party packages are also available.
 
 The [DRF Any Permissions][drf-any-permissions] packages provides a different permission behavior in contrast to REST framework.  Instead of all specified permissions being required, only one of the given permissions has to be true in order to get access to the view.
 
+## Composed Permissions
+
+The [Composed Permissions][composed-permissions] package provides a simple way to define complex and multi-depth (with logic operators) permission objects, using small and reusable components.
+
 [cite]: https://developer.apple.com/library/mac/#documentation/security/Conceptual/AuthenticationAndAuthorizationGuide/Authorization/Authorization.html
 [authentication]: authentication.md
 [throttling]: throttling.md
@@ -222,3 +226,4 @@ The [DRF Any Permissions][drf-any-permissions] packages provides a different per
 [2.2-announcement]: ../topics/2.2-announcement.md
 [filtering]: filtering.md
 [drf-any-permissions]: https://github.com/kevin-brown/drf-any-permissions
+[composed-permissions]: https://github.com/niwibe/djangorestframework-composed-permissions
diff --git a/docs/api-guide/relations.md b/docs/api-guide/relations.md
index aa14bc725..15ba9a3a1 100644
--- a/docs/api-guide/relations.md
+++ b/docs/api-guide/relations.md
@@ -214,8 +214,6 @@ Nested relationships can be expressed by using serializers as fields.
 
 If the field is used to represent a to-many relationship, you should add the `many=True` flag to the serializer field.
 
-Note that nested relationships are currently read-only.  For read-write relationships, you should use a flat relational style.
-
 ## Example
 
 For example, the following serializer:
diff --git a/docs/api-guide/renderers.md b/docs/api-guide/renderers.md
index 7fc1fc1fd..657377d92 100644
--- a/docs/api-guide/renderers.md
+++ b/docs/api-guide/renderers.md
@@ -88,7 +88,7 @@ The client may additionally include an `'indent'` media type parameter, in which
 
 **.format**: `'.json'`
 
-**.charset**: `utf-8`
+**.charset**: `None`
 
 ## UnicodeJSONRenderer
 
@@ -110,7 +110,7 @@ Both the `JSONRenderer` and `UnicodeJSONRenderer` styles conform to [RFC 4627][r
 
 **.format**: `'.json'`
 
-**.charset**: `utf-8`
+**.charset**: `None`
 
 ## JSONPRenderer
 
@@ -212,6 +212,20 @@ You can use `TemplateHTMLRenderer` either to return regular HTML pages using RES
 
 See also: `TemplateHTMLRenderer`
 
+## HTMLFormRenderer
+
+Renders data returned by a serializer into an HTML form.  The output of this renderer does not include the enclosing `<form>` tags or an submit actions, as you'll probably need those to include the desired method and URL.  Also note that the `HTMLFormRenderer` does not yet support including field error messages.
+
+Note that the template used by the `HTMLFormRenderer` class, and the context submitted to it **may be subject to change**.  If you need to use this renderer class it is advised that you either make a local copy of the class and templates, or follow the release note on REST framework upgrades closely.
+
+**.media_type**: `text/html`
+
+**.format**: `'.form'`
+
+**.charset**: `utf-8`
+
+**.template**: `'rest_framework/form.html'`
+
 ## BrowsableAPIRenderer
 
 Renders data into HTML for the Browsable API.  This renderer will determine which other renderer would have been given highest priority, and use that to display an API style response within the HTML page.
@@ -222,6 +236,8 @@ Renders data into HTML for the Browsable API.  This renderer will determine whic
 
 **.charset**: `utf-8`
 
+**.template**: `'rest_framework/api.html'`
+
 #### Customizing BrowsableAPIRenderer
 
 By default the response content will be rendered with the highest priority renderer apart from `BrowseableAPIRenderer`.  If you need to customize this behavior, for example to use HTML as the default return format, but use JSON in the browsable API, you can do so by overriding the `get_default_renderer()` method.  For example:
@@ -295,12 +311,15 @@ By default renderer classes are assumed to be using the `UTF-8` encoding.  To us
 
 Note that if a renderer class returns a unicode string, then the response content will be coerced into a bytestring by the `Response` class, with the `charset` attribute set on the renderer used to determine the encoding.
 
-If the renderer returns a bytestring representing raw binary content, you should set a charset value of `None`, which will ensure the `Content-Type` header of the response will not have a `charset` value set.  Doing so will also ensure that the browsable API will not attempt to display the binary content as a string.
+If the renderer returns a bytestring representing raw binary content, you should set a charset value of `None`, which will ensure the `Content-Type` header of the response will not have a `charset` value set.
+
+In some cases you may also want to set the `render_style` attribute to `'binary'`.  Doing so will also ensure that the browsable API will not attempt to display the binary content as a string.
 
     class JPEGRenderer(renderers.BaseRenderer):
         media_type = 'image/jpeg'
         format = 'jpg'
         charset = None
+        render_style = 'binary'
 
         def render(self, data, media_type=None, renderer_context=None):
             return data
diff --git a/docs/api-guide/requests.md b/docs/api-guide/requests.md
index 39a34fcfb..0696fedf6 100644
--- a/docs/api-guide/requests.md
+++ b/docs/api-guide/requests.md
@@ -117,7 +117,7 @@ For more information see the [browser enhancements documentation].
 
 # Standard HttpRequest attributes
 
-As REST framework's `Request` extends Django's `HttpRequest`, all the other standard attributes and methods are also available.  For example the `request.META` dictionary is available as normal.
+As REST framework's `Request` extends Django's `HttpRequest`, all the other standard attributes and methods are also available.  For example the `request.META` and `request.session` dictionaries are available as normal.
 
 Note that due to implementation reasons the `Request` class does not inherit from `HttpRequest` class, but instead extends the class using composition.
 
diff --git a/docs/api-guide/serializers.md b/docs/api-guide/serializers.md
index d9fd46437..5d7e2ac87 100644
--- a/docs/api-guide/serializers.md
+++ b/docs/api-guide/serializers.md
@@ -184,7 +184,7 @@ If a nested representation may optionally accept the `None` value you should pas
         content = serializers.CharField(max_length=200)
         created = serializers.DateTimeField()
 
-Similarly if a nested representation should be a list of items, you should the `many=True` flag to the nested serialized.
+Similarly if a nested representation should be a list of items, you should pass the `many=True` flag to the nested serialized.
 
     class CommentSerializer(serializers.Serializer):
         user = UserSerializer(required=False)
@@ -192,11 +192,13 @@ Similarly if a nested representation should be a list of items, you should the `
         content = serializers.CharField(max_length=200)
         created = serializers.DateTimeField()
 
----
+Validation of nested objects will work the same as before.  Errors with nested objects will be nested under the field name of the nested object.
 
-**Note**: Nested serializers are only suitable for read-only representations, as there are cases where they would have ambiguous or non-obvious behavior if used when updating instances.  For read-write representations you should always use a flat representation, by using one of the `RelatedField` subclasses.
-
----
+    serializer = CommentSerializer(comment, data={'user': {'email': 'foobar', 'username': 'doe'}, 'content': 'baz'})
+    serializer.is_valid()
+    # False
+    serializer.errors
+    # {'user': {'email': [u'Enter a valid e-mail address.']}, 'created': [u'This field is required.']}
 
 ## Dealing with multiple objects
 
@@ -260,7 +262,7 @@ When performing a bulk update you may want to allow new items to be created, and
     serializer.save()  # `.save()` will be called on updated or newly created instances.
                        # `.delete()` will be called on any other items in the `queryset`.
 
-Passing `allow_add_remove=True` ensures that any update operations will completely overwrite the existing queryset, rather than simply updating existing objects. 
+Passing `allow_add_remove=True` ensures that any update operations will completely overwrite the existing queryset, rather than simply updating existing objects.
 
 #### How identity is determined when performing bulk updates
 
@@ -300,8 +302,7 @@ You can provide arbitrary additional context by passing a `context` argument whe
 
 The context dictionary can be used within any serializer field logic, such as a custom `.to_native()` method, by accessing the `self.context` attribute.
 
----
-
+-
 # ModelSerializer
 
 Often you'll want serializer classes that map closely to model definitions.
@@ -344,6 +345,8 @@ The default `ModelSerializer` uses primary keys for relationships, but you can a
 
 The `depth` option should be set to an integer value that indicates the depth of relationships that should be traversed before reverting to a flat representation.
 
+If you want to customize the way the serialization is done (e.g. using `allow_add_remove`) you'll need to define the field yourself.
+
 ## Specifying which fields should be read-only 
 
 You may wish to specify multiple fields as read-only.  Instead of adding each field explicitly with the `read_only=True` attribute, you may use the `read_only_fields` Meta option, like so:
diff --git a/docs/api-guide/settings.md b/docs/api-guide/settings.md
index fe7925a5a..542e8c5fa 100644
--- a/docs/api-guide/settings.md
+++ b/docs/api-guide/settings.md
@@ -127,6 +127,35 @@ Default: `None`
 
 The name of a query parameter, which can be used by the client to override the default page size to use for pagination.  If set to `None`, clients may not override the default page size.
 
+For example, given the following settings:
+
+    REST_FRAMEWORK = {
+    	'PAGINATE_BY': 10,
+    	'PAGINATE_BY_PARAM': 'page_size',
+    }
+
+A client would be able to modify the pagination size by using the `page_size` query parameter.  For example:
+
+    GET http://example.com/api/accounts?page_size=25
+
+Default: `None`
+
+#### MAX_PAGINATE_BY
+
+The maximum page size to allow when the page size is specified by the client.  If set to `None`, then no maximum limit is applied.
+
+For example, given the following settings:
+
+    REST_FRAMEWORK = {
+    	'PAGINATE_BY': 10,
+    	'PAGINATE_BY_PARAM': 'page_size',
+        'MAX_PAGINATE_BY': 100
+    }
+
+A client request like the following would return a paginated list of up to 100 items.
+
+    GET http://example.com/api/accounts?page_size=999
+
 Default: `None`
 
 ---
diff --git a/docs/api-guide/testing.md b/docs/api-guide/testing.md
index b3880f8f0..35c1f7660 100644
--- a/docs/api-guide/testing.md
+++ b/docs/api-guide/testing.md
@@ -2,7 +2,7 @@
 
 # Testing
 
-> Code without tests is broken as designed
+> Code without tests is broken as designed.
 >
 > &mdash; [Jacob Kaplan-Moss][cite]
 
diff --git a/docs/api-guide/throttling.md b/docs/api-guide/throttling.md
index 42f9c228d..cc4692171 100644
--- a/docs/api-guide/throttling.md
+++ b/docs/api-guide/throttling.md
@@ -70,6 +70,13 @@ Or, if you're using the `@api_view` decorator with function based views.
 
 The throttle classes provided by REST framework use Django's cache backend.  You should make sure that you've set appropriate [cache settings][cache-setting].  The default value of `LocMemCache` backend should be okay for simple setups.  See Django's [cache documentation][cache-docs] for more details.
 
+If you need to use a cache other than `'default'`, you can do so by creating a custom throttle class and setting the `cache` attribute.  For example:
+
+    class CustomAnonRateThrottle(AnonRateThrottle):
+        cache = get_cache('alternate') 
+
+You'll need to rememeber to also set your custom throttle class in the `'DEFAULT_THROTTLE_CLASSES'` settings key, or using the `throttle_classes` view attribute.
+
 ---
 
 # API Reference
diff --git a/docs/api-guide/viewsets.md b/docs/api-guide/viewsets.md
index c4a2d61ea..6498e1779 100644
--- a/docs/api-guide/viewsets.md
+++ b/docs/api-guide/viewsets.md
@@ -151,6 +151,9 @@ By default, the decorators will route `GET` requests, but may also accept other
         @detail_route(methods=['post', 'delete'])
         def unset_password(self, request, pk=None):
            ...
+           
+The two new actions will then be available at the urls `^users/{pk}/set_password/$` and `^users/{pk}/unset_password/$`
+
 ---
 
 # API Reference
diff --git a/docs/index.md b/docs/index.md
index a0ae2984d..e0a2e911b 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -200,7 +200,7 @@ To run the tests against all supported configurations, first install [the tox te
 
 ## Support
 
-For support please see the [REST framework discussion group][group], try the  `#restframework` channel on `irc.freenode.net`, or raise a  question on [Stack Overflow][stack-overflow], making sure to include the ['django-rest-framework'][django-rest-framework-tag] tag.
+For support please see the [REST framework discussion group][group], try the  `#restframework` channel on `irc.freenode.net`, search [the IRC archives][botbot], or raise a  question on [Stack Overflow][stack-overflow], making sure to include the ['django-rest-framework'][django-rest-framework-tag] tag.
 
 [Paid support is available][paid-support] from [DabApps][dabapps], and can include work on REST framework core, or support with building your REST framework API.  Please [contact DabApps][contact-dabapps] if you'd like to discuss commercial support options.
 
@@ -307,6 +307,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 [tox]: http://testrun.org/tox/latest/
 
 [group]: https://groups.google.com/forum/?fromgroups#!forum/django-rest-framework
+[botbot]: https://botbot.me/freenode/restframework/
 [stack-overflow]: http://stackoverflow.com/
 [django-rest-framework-tag]: http://stackoverflow.com/questions/tagged/django-rest-framework
 [django-tag]: http://stackoverflow.com/questions/tagged/django
diff --git a/docs/topics/credits.md b/docs/topics/credits.md
index a894ee7cc..b2d3d5d29 100644
--- a/docs/topics/credits.md
+++ b/docs/topics/credits.md
@@ -159,6 +159,13 @@ The following people have helped make REST framework great.
 * Jeremy Satterfield - [jsatt]
 * Christopher Paolini - [chrispaolini]
 * Filipe A Ximenes - [filipeximenes]
+* Ramiro Morales - [ramiro]
+* Krzysztof Jurewicz - [krzysiekj]
+* Eric Buehl - [ericbuehl]
+* Kristian Øllegaard - [kristianoellegaard]
+* Alexander Akhmetov - [alexander-akhmetov]
+* Andrey Antukh - [niwibe]
+* Mathieu Pillard - [diox]
 
 Many thanks to everyone who's contributed to the project.
 
@@ -354,3 +361,10 @@ You can also contact [@_tomchristie][twitter] directly on twitter.
 [jsatt]: https://github.com/jsatt
 [chrispaolini]: https://github.com/chrispaolini
 [filipeximenes]: https://github.com/filipeximenes
+[ramiro]: https://github.com/ramiro
+[krzysiekj]: https://github.com/krzysiekj
+[ericbuehl]: https://github.com/ericbuehl
+[kristianoellegaard]: https://github.com/kristianoellegaard
+[alexander-akhmetov]: https://github.com/alexander-akhmetov
+[niwibe]: https://github.com/niwibe
+[diox]: https://github.com/diox
diff --git a/docs/topics/release-notes.md b/docs/topics/release-notes.md
index 58f85c6f2..5e3aa2f0b 100644
--- a/docs/topics/release-notes.md
+++ b/docs/topics/release-notes.md
@@ -45,8 +45,13 @@ You can determine your currently installed version using `pip freeze`:
 * `@detail_route` and `@list_route` decorators replace `@action` and `@link`.
 * `six` no longer bundled.  For Django <= 1.4.1, install `six` package.
 * Support customizable view name and description functions, using the `VIEW_NAME_FUNCTION` and `VIEW_DESCRIPTION_FUNCTION` settings.
+* Added `MAX_PAGINATE_BY` setting and `max_paginate_by` generic view attribute.
+* Added `cache` attribute to throttles to allow overriding of default cache.
 * Bugfix: `?page_size=0` query parameter now falls back to default page size for view, instead of always turning pagination off.
 * Bugfix: `required=True` argument fixed for boolean serializer fields.
+* Bugfix: `client.force_authenticate(None)` should also clear session info if it exists.
+* Bugfix: Client sending emptry string instead of file now clears `FileField`.
+* Bugfix: Empty values on ChoiceFields with `required=False` now consistently return `None`.
 
 ### 2.3.7
 
diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 518ba41af..b3a9b0dfe 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -301,7 +301,10 @@ class WritableField(Field):
         try:
             if self.use_files:
                 files = files or {}
-                native = files[field_name]
+                try:
+                    native = files[field_name]
+                except KeyError:
+                    native = data[field_name]
             else:
                 native = data[field_name]
         except KeyError:
@@ -504,6 +507,11 @@ class ChoiceField(WritableField):
                     return True
         return False
 
+    def from_native(self, value):
+        if value in validators.EMPTY_VALUES:
+            return None
+        return super(ChoiceField, self).from_native(value)
+
 
 class EmailField(CharField):
     type_name = 'EmailField'
diff --git a/rest_framework/generics.py b/rest_framework/generics.py
index 8e6b8e26c..851f8474f 100644
--- a/rest_framework/generics.py
+++ b/rest_framework/generics.py
@@ -14,13 +14,15 @@ from rest_framework.settings import api_settings
 import warnings
 
 
-def strict_positive_int(integer_string):
+def strict_positive_int(integer_string, cutoff=None):
     """
     Cast a string to a strictly positive integer.
     """
     ret = int(integer_string)
     if ret <= 0:
         raise ValueError()
+    if cutoff:
+        ret = min(ret, cutoff)
     return ret
 
 def get_object_or_404(queryset, **filter_kwargs):
@@ -56,6 +58,7 @@ class GenericAPIView(views.APIView):
     # Pagination settings
     paginate_by = api_settings.PAGINATE_BY
     paginate_by_param = api_settings.PAGINATE_BY_PARAM
+    max_paginate_by = api_settings.MAX_PAGINATE_BY
     pagination_serializer_class = api_settings.DEFAULT_PAGINATION_SERIALIZER_CLASS
     page_kwarg = 'page'
 
@@ -205,9 +208,11 @@ class GenericAPIView(views.APIView):
                           DeprecationWarning, stacklevel=2)
 
         if self.paginate_by_param:
-            query_params = self.request.QUERY_PARAMS
             try:
-                return strict_positive_int(query_params[self.paginate_by_param])
+                return strict_positive_int(
+                    self.request.QUERY_PARAMS[self.paginate_by_param],
+                    cutoff=self.max_paginate_by
+                )
             except (KeyError, ValueError):
                 pass
 
diff --git a/rest_framework/mixins.py b/rest_framework/mixins.py
index 679dfa6c3..2c85d157a 100644
--- a/rest_framework/mixins.py
+++ b/rest_framework/mixins.py
@@ -142,11 +142,16 @@ class UpdateModelMixin(object):
         try:
             return self.get_object()
         except Http404:
-            # If this is a PUT-as-create operation, we need to ensure that
-            # we have relevant permissions, as if this was a POST request.
-            # This will either raise a PermissionDenied exception,
-            # or simply return None
-            self.check_permissions(clone_request(self.request, 'POST'))
+            if self.request.method == 'PUT':
+                # For PUT-as-create operation, we need to ensure that we have
+                # relevant permissions, as if this was a POST request.  This
+                # will either raise a PermissionDenied exception, or simply
+                # return None.
+                self.check_permissions(clone_request(self.request, 'POST'))
+            else:
+                # PATCH requests where the object does not exist should still
+                # return a 404 response.
+                raise
 
     def pre_save(self, obj):
         """
diff --git a/rest_framework/parsers.py b/rest_framework/parsers.py
index 96bfac84a..98fc03417 100644
--- a/rest_framework/parsers.py
+++ b/rest_framework/parsers.py
@@ -10,9 +10,9 @@ from django.core.files.uploadhandler import StopFutureHandlers
 from django.http import QueryDict
 from django.http.multipartparser import MultiPartParser as DjangoMultiPartParser
 from django.http.multipartparser import MultiPartParserError, parse_header, ChunkIter
-from rest_framework.compat import yaml, etree
+from rest_framework.compat import etree, six, yaml
 from rest_framework.exceptions import ParseError
-from rest_framework.compat import six
+from rest_framework import renderers
 import json
 import datetime
 import decimal
@@ -47,6 +47,7 @@ class JSONParser(BaseParser):
     """
 
     media_type = 'application/json'
+    renderer_class = renderers.UnicodeJSONRenderer
 
     def parse(self, stream, media_type=None, parser_context=None):
         """
@@ -121,7 +122,8 @@ class MultiPartParser(BaseParser):
         parser_context = parser_context or {}
         request = parser_context['request']
         encoding = parser_context.get('encoding', settings.DEFAULT_CHARSET)
-        meta = request.META
+        meta = request.META.copy()
+        meta['CONTENT_TYPE'] = media_type
         upload_handlers = request.upload_handlers
 
         try:
@@ -129,7 +131,7 @@ class MultiPartParser(BaseParser):
             data, files = parser.parse()
             return DataAndFiles(data, files)
         except MultiPartParserError as exc:
-            raise ParseError('Multipart form parse error - %s' % six.u(exc))
+            raise ParseError('Multipart form parse error - %s' % str(exc))
 
 
 class XMLParser(BaseParser):
diff --git a/rest_framework/relations.py b/rest_framework/relations.py
index f1f7dea72..417925b57 100644
--- a/rest_framework/relations.py
+++ b/rest_framework/relations.py
@@ -126,9 +126,9 @@ class RelatedField(WritableField):
             value = obj
 
             for component in source.split('.'):
-                value = get_component(value, component)
                 if value is None:
                     break
+                value = get_component(value, component)
         except ObjectDoesNotExist:
             return None
 
@@ -236,6 +236,8 @@ class PrimaryKeyRelatedField(RelatedField):
                 source = self.source or field_name
                 queryset = obj
                 for component in source.split('.'):
+                    if queryset is None:
+                        return []
                     queryset = get_component(queryset, component)
 
             # Forward relationship
@@ -556,8 +558,13 @@ class HyperlinkedIdentityField(Field):
         May raise a `NoReverseMatch` if the `view_name` and `lookup_field`
         attributes are not configured to correctly match the URL conf.
         """
-        lookup_field = getattr(obj, self.lookup_field)
+        lookup_field = getattr(obj, self.lookup_field, None)
         kwargs = {self.lookup_field: lookup_field}
+
+        # Handle unsaved object case
+        if lookup_field is None:
+            return None
+
         try:
             return reverse(view_name, kwargs=kwargs, request=request, format=format)
         except NoReverseMatch:
diff --git a/rest_framework/renderers.py b/rest_framework/renderers.py
index 1006e26cf..fca67eeeb 100644
--- a/rest_framework/renderers.py
+++ b/rest_framework/renderers.py
@@ -21,10 +21,10 @@ from rest_framework.compat import six
 from rest_framework.compat import smart_text
 from rest_framework.compat import yaml
 from rest_framework.settings import api_settings
-from rest_framework.request import clone_request
+from rest_framework.request import is_form_media_type, override_method
 from rest_framework.utils import encoders
 from rest_framework.utils.breadcrumbs import get_breadcrumbs
-from rest_framework import exceptions, parsers, status, VERSION
+from rest_framework import exceptions, status, VERSION
 
 
 class BaseRenderer(object):
@@ -36,6 +36,7 @@ class BaseRenderer(object):
     media_type = None
     format = None
     charset = 'utf-8'
+    render_style = 'text'
 
     def render(self, data, accepted_media_type=None, renderer_context=None):
         raise NotImplemented('Renderer class requires .render() to be implemented')
@@ -51,16 +52,17 @@ class JSONRenderer(BaseRenderer):
     format = 'json'
     encoder_class = encoders.JSONEncoder
     ensure_ascii = True
-    charset = 'utf-8'
-    # Note that JSON encodings must be utf-8, utf-16 or utf-32.
+    charset = None
+    # JSON is a binary encoding, that can be encoded as utf-8, utf-16 or utf-32.
     # See: http://www.ietf.org/rfc/rfc4627.txt
+    # Also: http://lucumr.pocoo.org/2013/7/19/application-mimetypes-and-encodings/
 
     def render(self, data, accepted_media_type=None, renderer_context=None):
         """
         Render `data` into JSON.
         """
         if data is None:
-            return ''
+            return bytes()
 
         # If 'indent' is provided in the context, then pretty print the result.
         # E.g. If we're being called by the BrowsableAPIRenderer.
@@ -85,13 +87,12 @@ class JSONRenderer(BaseRenderer):
         # and may (or may not) be unicode.
         # On python 3.x json.dumps() returns unicode strings.
         if isinstance(ret, six.text_type):
-            return bytes(ret.encode(self.charset))
+            return bytes(ret.encode('utf-8'))
         return ret
 
 
 class UnicodeJSONRenderer(JSONRenderer):
     ensure_ascii = False
-    charset = 'utf-8'
     """
     Renderer which serializes to JSON.
     Does *not* apply JSON's character escaping for non-ascii characters.
@@ -108,6 +109,7 @@ class JSONPRenderer(JSONRenderer):
     format = 'jsonp'
     callback_parameter = 'callback'
     default_callback = 'callback'
+    charset = 'utf-8'
 
     def get_callback(self, renderer_context):
         """
@@ -316,6 +318,90 @@ class StaticHTMLRenderer(TemplateHTMLRenderer):
         return data
 
 
+class HTMLFormRenderer(BaseRenderer):
+    """
+    Renderers serializer data into an HTML form.
+
+    If the serializer was instantiated without an object then this will
+    return an HTML form not bound to any object,
+    otherwise it will return an HTML form with the appropriate initial data
+    populated from the object.
+
+    Note that rendering of field and form errors is not currently supported.
+    """
+    media_type = 'text/html'
+    format = 'form'
+    template = 'rest_framework/form.html'
+    charset = 'utf-8'
+
+    def data_to_form_fields(self, data):
+        fields = {}
+        for key, val in data.fields.items():
+            if getattr(val, 'read_only', True):
+                # Don't include read-only fields.
+                continue
+
+            if getattr(val, 'fields', None):
+                # Nested data not supported by HTML forms.
+                continue
+
+            kwargs = {}
+            kwargs['required'] = val.required
+
+            #if getattr(v, 'queryset', None):
+            #    kwargs['queryset'] = v.queryset
+
+            if getattr(val, 'choices', None) is not None:
+                kwargs['choices'] = val.choices
+
+            if getattr(val, 'regex', None) is not None:
+                kwargs['regex'] = val.regex
+
+            if getattr(val, 'widget', None):
+                widget = copy.deepcopy(val.widget)
+                kwargs['widget'] = widget
+
+            if getattr(val, 'default', None) is not None:
+                kwargs['initial'] = val.default
+
+            if getattr(val, 'label', None) is not None:
+                kwargs['label'] = val.label
+
+            if getattr(val, 'help_text', None) is not None:
+                kwargs['help_text'] = val.help_text
+
+            fields[key] = val.form_field_class(**kwargs)
+
+        return fields
+
+    def render(self, data, accepted_media_type=None, renderer_context=None):
+        """
+        Render serializer data and return an HTML form, as a string.
+        """
+        # The HTMLFormRenderer currently uses something of a hack to render
+        # the content, by translating each of the serializer fields into
+        # an html form field, creating a dynamic form using those fields,
+        # and then rendering that form.
+
+        # This isn't strictly neccessary, as we could render the serilizer
+        # fields to HTML directly.  The implementation is historical and will
+        # likely change at some point.
+
+        self.renderer_context = renderer_context or {}
+        request = renderer_context['request']
+
+        # Creating an on the fly form see:
+        # http://stackoverflow.com/questions/3915024/dynamically-creating-classes-python
+        fields = self.data_to_form_fields(data)
+        DynamicForm = type(str('DynamicForm'), (forms.Form,), fields)
+        data = None if data.empty else data
+
+        template = loader.get_template(self.template)
+        context = RequestContext(request, {'form': DynamicForm(data)})
+
+        return template.render(context)
+
+
 class BrowsableAPIRenderer(BaseRenderer):
     """
     HTML renderer used to self-document the API.
@@ -324,6 +410,7 @@ class BrowsableAPIRenderer(BaseRenderer):
     format = 'api'
     template = 'rest_framework/api.html'
     charset = 'utf-8'
+    form_renderer_class = HTMLFormRenderer
 
     def get_default_renderer(self, view):
         """
@@ -348,7 +435,10 @@ class BrowsableAPIRenderer(BaseRenderer):
         renderer_context['indent'] = 4
         content = renderer.render(data, accepted_media_type, renderer_context)
 
-        if renderer.charset is None:
+        render_style = getattr(renderer, 'render_style', 'text')
+        assert render_style in ['text', 'binary'], 'Expected .render_style ' \
+            '"text" or "binary", but got "%s"' % render_style
+        if render_style == 'binary':
             return '[%d bytes of binary content]' % len(content)
 
         return content
@@ -371,130 +461,99 @@ class BrowsableAPIRenderer(BaseRenderer):
             return False  # Doesn't have permissions
         return True
 
-    def serializer_to_form_fields(self, serializer):
-        fields = {}
-        for k, v in serializer.get_fields().items():
-            if getattr(v, 'read_only', True):
-                continue
-
-            kwargs = {}
-            kwargs['required'] = v.required
-
-            #if getattr(v, 'queryset', None):
-            #    kwargs['queryset'] = v.queryset
-
-            if getattr(v, 'choices', None) is not None:
-                kwargs['choices'] = v.choices
-
-            if getattr(v, 'regex', None) is not None:
-                kwargs['regex'] = v.regex
-
-            if getattr(v, 'widget', None):
-                widget = copy.deepcopy(v.widget)
-                kwargs['widget'] = widget
-
-            if getattr(v, 'default', None) is not None:
-                kwargs['initial'] = v.default
-
-            if getattr(v, 'label', None) is not None:
-                kwargs['label'] = v.label
-
-            if getattr(v, 'help_text', None) is not None:
-                kwargs['help_text'] = v.help_text
-
-            fields[k] = v.form_field_class(**kwargs)
-
-        return fields
-
-    def _get_form(self, view, method, request):
-        # We need to impersonate a request with the correct method,
-        # so that eg. any dynamic get_serializer_class methods return the
-        # correct form for each method.
-        restore = view.request
-        request = clone_request(request, method)
-        view.request = request
-        try:
-            return self.get_form(view, method, request)
-        finally:
-            view.request = restore
-
-    def _get_raw_data_form(self, view, method, request, media_types):
-        # We need to impersonate a request with the correct method,
-        # so that eg. any dynamic get_serializer_class methods return the
-        # correct form for each method.
-        restore = view.request
-        request = clone_request(request, method)
-        view.request = request
-        try:
-            return self.get_raw_data_form(view, method, request, media_types)
-        finally:
-            view.request = restore
-
-    def get_form(self, view, method, request):
+    def get_rendered_html_form(self, view, method, request):
         """
-        Get a form, possibly bound to either the input or output data.
-        In the absence on of the Resource having an associated form then
-        provide a form that can be used to submit arbitrary content.
+        Return a string representing a rendered HTML form, possibly bound to
+        either the input or output data.
+
+        In the absence of the View having an associated form then return None.
         """
-        obj = getattr(view, 'object', None)
-        if not self.show_form_for_method(view, method, request, obj):
-            return
+        with override_method(view, request, method) as request:
+            obj = getattr(view, 'object', None)
+            if not self.show_form_for_method(view, method, request, obj):
+                return
 
-        if method in ('DELETE', 'OPTIONS'):
-            return True  # Don't actually need to return a form
+            if method in ('DELETE', 'OPTIONS'):
+                return True  # Don't actually need to return a form
 
-        if not getattr(view, 'get_serializer', None) or not parsers.FormParser in view.parser_classes:
-            return
+            if (not getattr(view, 'get_serializer', None)
+                or not any(is_form_media_type(parser.media_type) for parser in view.parser_classes)):
+                return
 
-        serializer = view.get_serializer(instance=obj)
-        fields = self.serializer_to_form_fields(serializer)
+            serializer = view.get_serializer(instance=obj)
 
-        # Creating an on the fly form see:
-        # http://stackoverflow.com/questions/3915024/dynamically-creating-classes-python
-        OnTheFlyForm = type(str("OnTheFlyForm"), (forms.Form,), fields)
-        data = (obj is not None) and serializer.data or None
-        form_instance = OnTheFlyForm(data)
-        return form_instance
+            data = serializer.data
+            form_renderer = self.form_renderer_class()
+            return form_renderer.render(data, self.accepted_media_type, self.renderer_context)
 
-    def get_raw_data_form(self, view, method, request, media_types):
+    def get_raw_data_form(self, view, method, request):
         """
         Returns a form that allows for arbitrary content types to be tunneled
         via standard HTML forms.
         (Which are typically application/x-www-form-urlencoded)
         """
+        with override_method(view, request, method) as request:
+            # If we're not using content overloading there's no point in
+            # supplying a generic form, as the view won't treat the form's
+            # value as the content of the request.
+            if not (api_settings.FORM_CONTENT_OVERRIDE
+                    and api_settings.FORM_CONTENTTYPE_OVERRIDE):
+                return None
 
-        # If we're not using content overloading there's no point in supplying a generic form,
-        # as the view won't treat the form's value as the content of the request.
-        if not (api_settings.FORM_CONTENT_OVERRIDE
-                and api_settings.FORM_CONTENTTYPE_OVERRIDE):
-            return None
+            # Check permissions
+            obj = getattr(view, 'object', None)
+            if not self.show_form_for_method(view, method, request, obj):
+                return
 
-        # Check permissions
-        obj = getattr(view, 'object', None)
-        if not self.show_form_for_method(view, method, request, obj):
-            return
+            # If possible, serialize the initial content for the generic form
+            default_parser = view.parser_classes[0]
+            renderer_class = getattr(default_parser, 'renderer_class', None)
+            if (hasattr(view, 'get_serializer') and renderer_class):
+                # View has a serializer defined and parser class has a
+                # corresponding renderer that can be used to render the data.
 
-        content_type_field = api_settings.FORM_CONTENTTYPE_OVERRIDE
-        content_field = api_settings.FORM_CONTENT_OVERRIDE
-        choices = [(media_type, media_type) for media_type in media_types]
-        initial = media_types[0]
+                # Get a read-only version of the serializer
+                serializer = view.get_serializer(instance=obj)
+                if obj is None:
+                    for name, field in serializer.fields.items():
+                        if getattr(field, 'read_only', None):
+                            del serializer.fields[name]
 
-        # NB. http://jacobian.org/writing/dynamic-form-generation/
-        class GenericContentForm(forms.Form):
-            def __init__(self):
-                super(GenericContentForm, self).__init__()
+                # Render the raw data content
+                renderer = renderer_class()
+                accepted = self.accepted_media_type
+                context = self.renderer_context.copy()
+                context['indent'] = 4
+                content = renderer.render(serializer.data, accepted, context)
+            else:
+                content = None
 
-                self.fields[content_type_field] = forms.ChoiceField(
-                    label='Media type',
-                    choices=choices,
-                    initial=initial
-                )
-                self.fields[content_field] = forms.CharField(
-                    label='Content',
-                    widget=forms.Textarea
-                )
+            # Generate a generic form that includes a content type field,
+            # and a content field.
+            content_type_field = api_settings.FORM_CONTENTTYPE_OVERRIDE
+            content_field = api_settings.FORM_CONTENT_OVERRIDE
 
-        return GenericContentForm()
+            media_types = [parser.media_type for parser in view.parser_classes]
+            choices = [(media_type, media_type) for media_type in media_types]
+            initial = media_types[0]
+
+            # NB. http://jacobian.org/writing/dynamic-form-generation/
+            class GenericContentForm(forms.Form):
+                def __init__(self):
+                    super(GenericContentForm, self).__init__()
+
+                    self.fields[content_type_field] = forms.ChoiceField(
+                        label='Media type',
+                        choices=choices,
+                        initial=initial
+                    )
+                    self.fields[content_field] = forms.CharField(
+                        label='Content',
+                        widget=forms.Textarea,
+                        initial=content
+                    )
+
+            return GenericContentForm()
 
     def get_name(self, view):
         return view.get_view_name()
@@ -509,26 +568,25 @@ class BrowsableAPIRenderer(BaseRenderer):
         """
         Render the HTML for the browsable API representation.
         """
-        accepted_media_type = accepted_media_type or ''
-        renderer_context = renderer_context or {}
+        self.accepted_media_type = accepted_media_type or ''
+        self.renderer_context = renderer_context or {}
 
         view = renderer_context['view']
         request = renderer_context['request']
         response = renderer_context['response']
-        media_types = [parser.media_type for parser in view.parser_classes]
 
         renderer = self.get_default_renderer(view)
         content = self.get_content(renderer, data, accepted_media_type, renderer_context)
 
-        put_form = self._get_form(view, 'PUT', request)
-        post_form = self._get_form(view, 'POST', request)
-        patch_form = self._get_form(view, 'PATCH', request)
-        delete_form = self._get_form(view, 'DELETE', request)
-        options_form = self._get_form(view, 'OPTIONS', request)
+        put_form = self.get_rendered_html_form(view, 'PUT', request)
+        post_form = self.get_rendered_html_form(view, 'POST', request)
+        patch_form = self.get_rendered_html_form(view, 'PATCH', request)
+        delete_form = self.get_rendered_html_form(view, 'DELETE', request)
+        options_form = self.get_rendered_html_form(view, 'OPTIONS', request)
 
-        raw_data_put_form = self._get_raw_data_form(view, 'PUT', request, media_types)
-        raw_data_post_form = self._get_raw_data_form(view, 'POST', request, media_types)
-        raw_data_patch_form = self._get_raw_data_form(view, 'PATCH', request, media_types)
+        raw_data_put_form = self.get_raw_data_form(view, 'PUT', request)
+        raw_data_post_form = self.get_raw_data_form(view, 'POST', request)
+        raw_data_patch_form = self.get_raw_data_form(view, 'PATCH', request)
         raw_data_put_or_patch_form = raw_data_put_form or raw_data_patch_form
 
         name = self.get_name(view)
@@ -581,3 +639,4 @@ class MultiPartRenderer(BaseRenderer):
 
     def render(self, data, accepted_media_type=None, renderer_context=None):
         return encode_multipart(self.BOUNDARY, data)
+
diff --git a/rest_framework/request.py b/rest_framework/request.py
index 919716f49..977d4d965 100644
--- a/rest_framework/request.py
+++ b/rest_framework/request.py
@@ -28,6 +28,29 @@ def is_form_media_type(media_type):
             base_media_type == 'multipart/form-data')
 
 
+class override_method(object):
+    """
+    A context manager that temporarily overrides the method on a request,
+    additionally setting the `view.request` attribute.
+
+    Usage:
+
+        with override_method(view, request, 'POST') as request:
+            ... # Do stuff with `view` and `request`
+    """
+    def __init__(self, view, request, method):
+        self.view = view
+        self.request = request
+        self.method = method
+
+    def __enter__(self):
+        self.view.request = clone_request(self.request, self.method)
+        return self.view.request
+
+    def __exit__(self, *args, **kwarg):
+        self.view.request = self.request
+
+
 class Empty(object):
     """
     Placeholder for unset attributes.
diff --git a/rest_framework/routers.py b/rest_framework/routers.py
index b761ba9ae..1c7a81585 100644
--- a/rest_framework/routers.py
+++ b/rest_framework/routers.py
@@ -213,7 +213,11 @@ class SimpleRouter(BaseRouter):
         Given a viewset, return the portion of URL regex that is used
         to match against a single instance.
         """
-        base_regex = '(?P<{lookup_field}>[^/]+)'
+        if self.trailing_slash:
+            base_regex = '(?P<{lookup_field}>[^/]+)'
+        else:
+            # Don't consume `.json` style suffixes
+            base_regex = '(?P<{lookup_field}>[^/.]+)'
         lookup_field = getattr(viewset, 'lookup_field', 'pk')
         return base_regex.format(lookup_field=lookup_field)
 
diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index b38501574..f17757625 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -31,6 +31,9 @@ from rest_framework.relations import *
 from rest_framework.fields import *
 
 
+class RelationsList(list):
+    _deleted = []
+
 class NestedValidationError(ValidationError):
     """
     The default ValidationError behavior is to stringify each item in the list
@@ -160,7 +163,6 @@ class BaseSerializer(WritableField):
         self._data = None
         self._files = None
         self._errors = None
-        self._deleted = None
 
         if many and instance is not None and not hasattr(instance, '__iter__'):
             raise ValueError('instance should be a queryset or other iterable with many=True')
@@ -297,7 +299,8 @@ class BaseSerializer(WritableField):
         Serialize objects -> primitives.
         """
         ret = self._dict_class()
-        ret.fields = {}
+        ret.fields = self._dict_class()
+        ret.empty = obj is None
 
         for field_name, field in self.fields.items():
             field.initialize(parent=self, field_name=field_name)
@@ -330,14 +333,15 @@ class BaseSerializer(WritableField):
         if self.source == '*':
             return self.to_native(obj)
 
+        # Get the raw field value
         try:
             source = self.source or field_name
             value = obj
 
             for component in source.split('.'):
-                value = get_component(value, component)
                 if value is None:
                     break
+                value = get_component(value, component)
         except ObjectDoesNotExist:
             return None
 
@@ -372,6 +376,7 @@ class BaseSerializer(WritableField):
 
         # Set the serializer object if it exists
         obj = getattr(self.parent.object, field_name) if self.parent.object else None
+        obj = obj.all() if is_simple_callable(getattr(obj, 'all', None)) else obj
 
         if self.source == '*':
             if value:
@@ -385,7 +390,8 @@ class BaseSerializer(WritableField):
                     'data': value,
                     'context': self.context,
                     'partial': self.partial,
-                    'many': self.many
+                    'many': self.many,
+                    'allow_add_remove': self.allow_add_remove
                 }
                 serializer = self.__class__(**kwargs)
 
@@ -418,8 +424,17 @@ class BaseSerializer(WritableField):
         if self._errors is None:
             data, files = self.init_data, self.init_files
 
-            if self.many:
-                ret = []
+            if self.many is not None:
+                many = self.many
+            else:
+                many = hasattr(data, '__iter__') and not isinstance(data, (Page, dict, six.text_type))
+                if many:
+                    warnings.warn('Implict list/queryset serialization is deprecated. '
+                                  'Use the `many=True` flag when instantiating the serializer.',
+                                  DeprecationWarning, stacklevel=3)
+
+            if many:
+                ret = RelationsList()
                 errors = []
                 update = self.object is not None
 
@@ -446,8 +461,8 @@ class BaseSerializer(WritableField):
                         ret.append(self.from_native(item, None))
                         errors.append(self._errors)
 
-                    if update:
-                        self._deleted = identity_to_objects.values()
+                    if update and self.allow_add_remove:
+                        ret._deleted = identity_to_objects.values()
 
                     self._errors = any(errors) and errors or []
                 else:
@@ -490,12 +505,12 @@ class BaseSerializer(WritableField):
         """
         if isinstance(self.object, list):
             [self.save_object(item, **kwargs) for item in self.object]
+
+            if self.object._deleted:
+                [self.delete_object(item) for item in self.object._deleted]
         else:
             self.save_object(self.object, **kwargs)
 
-        if self.allow_add_remove and self._deleted:
-            [self.delete_object(item) for item in self._deleted]
-
         return self.object
 
     def metadata(self):
@@ -771,9 +786,12 @@ class ModelSerializer(Serializer):
         cls = self.opts.model
         opts = get_concrete_model(cls)._meta
         exclusions = [field.name for field in opts.fields + opts.many_to_many]
+
         for field_name, field in self.fields.items():
             field_name = field.source or field_name
-            if field_name in exclusions and not field.read_only:
+            if field_name in exclusions \
+                and not field.read_only \
+                and not isinstance(field, Serializer):
                 exclusions.remove(field_name)
         return exclusions
 
@@ -799,6 +817,7 @@ class ModelSerializer(Serializer):
         """
         m2m_data = {}
         related_data = {}
+        nested_forward_relations = {}
         meta = self.opts.model._meta
 
         # Reverse fk or one-to-one relations
@@ -818,6 +837,12 @@ class ModelSerializer(Serializer):
             if field.name in attrs:
                 m2m_data[field.name] = attrs.pop(field.name)
 
+        # Nested forward relations - These need to be marked so we can save
+        # them before saving the parent model instance.
+        for field_name in attrs.keys():
+            if isinstance(self.fields.get(field_name, None), Serializer):
+                nested_forward_relations[field_name] = attrs[field_name]
+
         # Update an existing instance...
         if instance is not None:
             for key, val in attrs.items():
@@ -833,6 +858,7 @@ class ModelSerializer(Serializer):
         # at the point of save.
         instance._related_data = related_data
         instance._m2m_data = m2m_data
+        instance._nested_forward_relations = nested_forward_relations
 
         return instance
 
@@ -848,6 +874,14 @@ class ModelSerializer(Serializer):
         """
         Save the deserialized object and return it.
         """
+        if getattr(obj, '_nested_forward_relations', None):
+            # Nested relationships need to be saved before we can save the
+            # parent instance.
+            for field_name, sub_object in obj._nested_forward_relations.items():
+                if sub_object:
+                    self.save_object(sub_object)
+                setattr(obj, field_name, sub_object)
+
         obj.save(**kwargs)
 
         if getattr(obj, '_m2m_data', None):
@@ -857,7 +891,25 @@ class ModelSerializer(Serializer):
 
         if getattr(obj, '_related_data', None):
             for accessor_name, related in obj._related_data.items():
-                setattr(obj, accessor_name, related)
+                if isinstance(related, RelationsList):
+                    # Nested reverse fk relationship
+                    for related_item in related:
+                        fk_field = obj._meta.get_field_by_name(accessor_name)[0].field.name
+                        setattr(related_item, fk_field, obj)
+                        self.save_object(related_item)
+
+                    # Delete any removed objects
+                    if related._deleted:
+                        [self.delete_object(item) for item in related._deleted]
+
+                elif isinstance(related, models.Model):
+                    # Nested reverse one-one relationship
+                    fk_field = obj._meta.get_field_by_name(accessor_name)[0].field.name
+                    setattr(related, fk_field, obj)
+                    self.save_object(related)
+                else:
+                    # Reverse FK or reverse one-one
+                    setattr(obj, accessor_name, related)
             del(obj._related_data)
 
 
@@ -879,6 +931,7 @@ class HyperlinkedModelSerializer(ModelSerializer):
     _options_class = HyperlinkedModelSerializerOptions
     _default_view_name = '%(model_name)s-detail'
     _hyperlink_field_class = HyperlinkedRelatedField
+    _hyperlink_identify_field_class = HyperlinkedIdentityField
 
     def get_default_fields(self):
         fields = super(HyperlinkedModelSerializer, self).get_default_fields()
@@ -887,7 +940,7 @@ class HyperlinkedModelSerializer(ModelSerializer):
             self.opts.view_name = self._get_default_view_name(self.opts.model)
 
         if 'url' not in fields:
-            url_field = HyperlinkedIdentityField(
+            url_field = self._hyperlink_identify_field_class(
                 view_name=self.opts.view_name,
                 lookup_field=self.opts.lookup_field
             )
diff --git a/rest_framework/settings.py b/rest_framework/settings.py
index 7d25e5131..8c0847512 100644
--- a/rest_framework/settings.py
+++ b/rest_framework/settings.py
@@ -48,7 +48,6 @@ DEFAULTS = {
     ),
     'DEFAULT_THROTTLE_CLASSES': (
     ),
-
     'DEFAULT_CONTENT_NEGOTIATION_CLASS':
         'rest_framework.negotiation.DefaultContentNegotiation',
 
@@ -68,15 +67,16 @@ DEFAULTS = {
     # Pagination
     'PAGINATE_BY': None,
     'PAGINATE_BY_PARAM': None,
-
-    # View configuration
-    'VIEW_NAME_FUNCTION': 'rest_framework.views.get_view_name',
-    'VIEW_DESCRIPTION_FUNCTION': 'rest_framework.views.get_view_description',
+    'MAX_PAGINATE_BY': None,
 
     # Authentication
     'UNAUTHENTICATED_USER': 'django.contrib.auth.models.AnonymousUser',
     'UNAUTHENTICATED_TOKEN': None,
 
+    # View configuration
+    'VIEW_NAME_FUNCTION': 'rest_framework.views.get_view_name',
+    'VIEW_DESCRIPTION_FUNCTION': 'rest_framework.views.get_view_description',
+
     # Testing
     'TEST_REQUEST_RENDERER_CLASSES': (
         'rest_framework.renderers.MultiPartRenderer',
diff --git a/rest_framework/static/rest_framework/js/default.js b/rest_framework/static/rest_framework/js/default.js
index c74829d7d..bcb1964db 100644
--- a/rest_framework/static/rest_framework/js/default.js
+++ b/rest_framework/static/rest_framework/js/default.js
@@ -1,13 +1,56 @@
+function getCookie(c_name)
+{
+    // From http://www.w3schools.com/js/js_cookies.asp
+    var c_value = document.cookie;
+    var c_start = c_value.indexOf(" " + c_name + "=");
+    if (c_start == -1) {
+        c_start = c_value.indexOf(c_name + "=");
+    }
+    if (c_start == -1) {
+        c_value = null;
+    } else {
+        c_start = c_value.indexOf("=", c_start) + 1;
+        var c_end = c_value.indexOf(";", c_start);
+        if (c_end == -1) {
+            c_end = c_value.length;
+        }
+        c_value = unescape(c_value.substring(c_start,c_end));
+    }
+    return c_value;
+}
+
+// JSON highlighting.
 prettyPrint();
 
+// Bootstrap tooltips.
 $('.js-tooltip').tooltip({
     delay: 1000
 });
 
+// Deal with rounded tab styling after tab clicks.
 $('a[data-toggle="tab"]:first').on('shown', function (e) {
     $(e.target).parents('.tabbable').addClass('first-tab-active');
 });
 $('a[data-toggle="tab"]:not(:first)').on('shown', function (e) {
     $(e.target).parents('.tabbable').removeClass('first-tab-active');
 });
-$('.form-switcher a:first').tab('show');
+
+$('a[data-toggle="tab"]').click(function(){
+    document.cookie="tabstyle=" + this.name + "; path=/";
+});
+
+// Store tab preference in cookies & display appropriate tab on load.
+var selectedTab = null;
+var selectedTabName = getCookie('tabstyle');
+
+if (selectedTabName) {
+    selectedTab = $('.form-switcher a[name=' + selectedTabName + ']');
+}
+
+if (selectedTab && selectedTab.length > 0) {
+    // Display whichever tab is selected.
+    selectedTab.tab('show');
+} else {
+    // If no tab selected, display rightmost tab.
+    $('.form-switcher a:first').tab('show');
+}
diff --git a/rest_framework/templates/rest_framework/base.html b/rest_framework/templates/rest_framework/base.html
index 51f9c2916..aa90e90c4 100644
--- a/rest_framework/templates/rest_framework/base.html
+++ b/rest_framework/templates/rest_framework/base.html
@@ -128,17 +128,17 @@
                 <div {% if post_form %}class="tabbable"{% endif %}>
                     {% if post_form %}
                     <ul class="nav nav-tabs form-switcher">
-                        <li><a href="#object-form" data-toggle="tab">HTML form</a></li>
-                        <li><a href="#generic-content-form" data-toggle="tab">Raw data</a></li>
+                        <li><a name='html-tab' href="#object-form" data-toggle="tab">HTML form</a></li>
+                        <li><a name='raw-tab' href="#generic-content-form" data-toggle="tab">Raw data</a></li>
                     </ul>
                     {% endif %}
                     <div class="well tab-content">
                         {% if post_form %}
                         <div class="tab-pane" id="object-form">
                             {% with form=post_form %}
-                            <form action="{{ request.get_full_path }}" method="POST" {% if form.is_multipart %}enctype="multipart/form-data"{% endif %} class="form-horizontal">
+                            <form action="{{ request.get_full_path }}" method="POST" enctype="multipart/form-data" class="form-horizontal">
                                 <fieldset>
-                                    {% include "rest_framework/form.html" %}
+                                    {{ post_form }}
                                     <div class="form-actions">
                                         <button class="btn btn-primary" title="Make a POST request on the {{ name }} resource">POST</button>
                                     </div>
@@ -167,23 +167,21 @@
                 <div {% if put_form %}class="tabbable"{% endif %}>
                     {% if put_form %}
                     <ul class="nav nav-tabs form-switcher">
-                        <li><a href="#object-form" data-toggle="tab">HTML form</a></li>
-                        <li><a href="#generic-content-form" data-toggle="tab">Raw data</a></li>
+                        <li><a name='html-tab' href="#object-form" data-toggle="tab">HTML form</a></li>
+                        <li><a  name='raw-tab' href="#generic-content-form" data-toggle="tab">Raw data</a></li>
                     </ul>
                     {% endif %}
                     <div class="well tab-content">
                         {% if put_form %}
                         <div class="tab-pane" id="object-form">
-                            {% with form=put_form %}
-                            <form action="{{ request.get_full_path }}" method="POST" {% if form.is_multipart %}enctype="multipart/form-data"{% endif %} class="form-horizontal">
+                            <form action="{{ request.get_full_path }}" method="POST" enctype="multipart/form-data" class="form-horizontal">
                                 <fieldset>
-                                    {% include "rest_framework/form.html" %}
+                                    {{ put_form }}
                                     <div class="form-actions">
                                         <button class="btn btn-primary js-tooltip" name="{{ api_settings.FORM_METHOD_OVERRIDE }}" value="PUT" title="Make a PUT request on the {{ name }} resource">PUT</button>
                                     </div>
                                 </fieldset>
                             </form>
-                            {% endwith %}
                         </div>
                         {% endif %}
                         <div {% if put_form %}class="tab-pane"{% endif %} id="generic-content-form">
diff --git a/rest_framework/test.py b/rest_framework/test.py
index a18f5a293..234d10a4a 100644
--- a/rest_framework/test.py
+++ b/rest_framework/test.py
@@ -134,6 +134,8 @@ class APIClient(APIRequestFactory, DjangoClient):
         """
         self.handler._force_user = user
         self.handler._force_token = token
+        if user is None:
+            self.logout()  # Also clear any possible session info if required
 
     def request(self, **kwargs):
         # Ensure that any credentials set get added to every request.
diff --git a/rest_framework/tests/test_fields.py b/rest_framework/tests/test_fields.py
index ebccba7d1..34fbab9c9 100644
--- a/rest_framework/tests/test_fields.py
+++ b/rest_framework/tests/test_fields.py
@@ -688,6 +688,14 @@ class ChoiceFieldTests(TestCase):
         f = serializers.ChoiceField(required=False, choices=self.SAMPLE_CHOICES)
         self.assertEqual(f.choices, models.fields.BLANK_CHOICE_DASH + self.SAMPLE_CHOICES)
 
+    def test_from_native_empty(self):
+        """
+        Make sure from_native() returns None on empty param.
+        """
+        f = serializers.ChoiceField(choices=self.SAMPLE_CHOICES)
+        result = f.from_native('')
+        self.assertEqual(result, None)
+
 
 class EmailFieldTests(TestCase):
     """
diff --git a/rest_framework/tests/test_files.py b/rest_framework/tests/test_files.py
index 487046aca..c13c38b86 100644
--- a/rest_framework/tests/test_files.py
+++ b/rest_framework/tests/test_files.py
@@ -7,13 +7,13 @@ import datetime
 
 
 class UploadedFile(object):
-    def __init__(self, file, created=None):
+    def __init__(self, file=None, created=None):
         self.file = file
         self.created = created or datetime.datetime.now()
 
 
 class UploadedFileSerializer(serializers.Serializer):
-    file = serializers.FileField()
+    file = serializers.FileField(required=False)
     created = serializers.DateTimeField()
 
     def restore_object(self, attrs, instance=None):
@@ -47,5 +47,36 @@ class FileSerializerTests(TestCase):
         now = datetime.datetime.now()
 
         serializer = UploadedFileSerializer(data={'created': now})
+        self.assertTrue(serializer.is_valid())
+        self.assertEqual(serializer.object.created, now)
+        self.assertIsNone(serializer.object.file)
+
+    def test_remove_with_empty_string(self):
+        """
+        Passing empty string as data should cause file to be removed
+
+        Test for:
+        https://github.com/tomchristie/django-rest-framework/issues/937
+        """
+        now = datetime.datetime.now()
+        file = BytesIO(six.b('stuff'))
+        file.name = 'stuff.txt'
+        file.size = len(file.getvalue())
+
+        uploaded_file = UploadedFile(file=file, created=now)
+
+        serializer = UploadedFileSerializer(instance=uploaded_file, data={'created': now, 'file': ''})
+        self.assertTrue(serializer.is_valid())
+        self.assertEqual(serializer.object.created, uploaded_file.created)
+        self.assertIsNone(serializer.object.file)
+
+    def test_validation_error_with_non_file(self):
+        """
+        Passing non-files should raise a validation error.
+        """
+        now = datetime.datetime.now()
+        errmsg = 'No file was submitted. Check the encoding type on the form.'
+
+        serializer = UploadedFileSerializer(data={'created': now, 'file': 'abc'})
         self.assertFalse(serializer.is_valid())
-        self.assertIn('file', serializer.errors)
+        self.assertEqual(serializer.errors, {'file': [errmsg]})
diff --git a/rest_framework/tests/test_generics.py b/rest_framework/tests/test_generics.py
index 1550880b5..7a87d3892 100644
--- a/rest_framework/tests/test_generics.py
+++ b/rest_framework/tests/test_generics.py
@@ -338,6 +338,17 @@ class TestInstanceView(TestCase):
         new_obj = SlugBasedModel.objects.get(slug='test_slug')
         self.assertEqual(new_obj.text, 'foobar')
 
+    def test_patch_cannot_create_an_object(self):
+        """
+        PATCH requests should not be able to create objects.
+        """
+        data = {'text': 'foobar'}
+        request = factory.patch('/999', data, format='json')
+        with self.assertNumQueries(1):
+            response = self.view(request, pk=999).render()
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
+        self.assertFalse(self.objects.filter(id=999).exists())
+
 
 class TestOverriddenGetObject(TestCase):
     """
diff --git a/rest_framework/tests/test_pagination.py b/rest_framework/tests/test_pagination.py
index 85d4640ea..4170d4b64 100644
--- a/rest_framework/tests/test_pagination.py
+++ b/rest_framework/tests/test_pagination.py
@@ -42,6 +42,16 @@ class PaginateByParamView(generics.ListAPIView):
     paginate_by_param = 'page_size'
 
 
+class MaxPaginateByView(generics.ListAPIView):
+    """
+    View for testing custom max_paginate_by usage
+    """
+    model = BasicModel
+    paginate_by = 3
+    max_paginate_by = 5
+    paginate_by_param = 'page_size'
+
+
 class IntegrationTestPagination(TestCase):
     """
     Integration tests for paginated list views.
@@ -313,6 +323,43 @@ class TestCustomPaginateByParam(TestCase):
         self.assertEqual(response.data['results'], self.data[:5])
 
 
+class TestMaxPaginateByParam(TestCase):
+    """
+    Tests for list views with max_paginate_by kwarg
+    """
+
+    def setUp(self):
+        """
+        Create 13 BasicModel instances.
+        """
+        for i in range(13):
+            BasicModel(text=i).save()
+        self.objects = BasicModel.objects
+        self.data = [
+            {'id': obj.id, 'text': obj.text}
+            for obj in self.objects.all()
+        ]
+        self.view = MaxPaginateByView.as_view()
+
+    def test_max_paginate_by(self):
+        """
+        If max_paginate_by is set, it should limit page size for the view.
+        """
+        request = factory.get('/?page_size=10')
+        response = self.view(request).render()
+        self.assertEqual(response.data['count'], 13)
+        self.assertEqual(response.data['results'], self.data[:5])
+
+    def test_max_paginate_by_without_page_size_param(self):
+        """
+        If max_paginate_by is set, but client does not specifiy page_size,
+        standard `paginate_by` behavior should be used.
+        """
+        request = factory.get('/')
+        response = self.view(request).render()
+        self.assertEqual(response.data['results'], self.data[:3])
+
+
 ### Tests for context in pagination serializers
 
 class CustomField(serializers.Field):
diff --git a/rest_framework/tests/test_relations_nested.py b/rest_framework/tests/test_relations_nested.py
index f6d006b39..d393b0c35 100644
--- a/rest_framework/tests/test_relations_nested.py
+++ b/rest_framework/tests/test_relations_nested.py
@@ -1,107 +1,328 @@
 from __future__ import unicode_literals
+from django.db import models
 from django.test import TestCase
 from rest_framework import serializers
-from rest_framework.tests.models import ForeignKeyTarget, ForeignKeySource, NullableForeignKeySource, OneToOneTarget, NullableOneToOneSource
 
 
-class ForeignKeySourceSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = ForeignKeySource
-        fields = ('id', 'name', 'target')
-        depth = 1
+class OneToOneTarget(models.Model):
+    name = models.CharField(max_length=100)
 
 
-class ForeignKeyTargetSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = ForeignKeyTarget
-        fields = ('id', 'name', 'sources')
-        depth = 1
+class OneToOneSource(models.Model):
+    name = models.CharField(max_length=100)
+    target = models.OneToOneField(OneToOneTarget, related_name='source',
+                                  null=True, blank=True)
 
 
-class NullableForeignKeySourceSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = NullableForeignKeySource
-        fields = ('id', 'name', 'target')
-        depth = 1
+class OneToManyTarget(models.Model):
+    name = models.CharField(max_length=100)
 
 
-class NullableOneToOneTargetSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = OneToOneTarget
-        fields = ('id', 'name', 'nullable_source')
-        depth = 1
+class OneToManySource(models.Model):
+    name = models.CharField(max_length=100)
+    target = models.ForeignKey(OneToManyTarget, related_name='sources')
 
 
-class ReverseForeignKeyTests(TestCase):
+class ReverseNestedOneToOneTests(TestCase):
     def setUp(self):
-        target = ForeignKeyTarget(name='target-1')
-        target.save()
-        new_target = ForeignKeyTarget(name='target-2')
-        new_target.save()
+        class OneToOneSourceSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = OneToOneSource
+                fields = ('id', 'name')
+
+        class OneToOneTargetSerializer(serializers.ModelSerializer):
+            source = OneToOneSourceSerializer()
+
+            class Meta:
+                model = OneToOneTarget
+                fields = ('id', 'name', 'source')
+
+        self.Serializer = OneToOneTargetSerializer
+
         for idx in range(1, 4):
-            source = ForeignKeySource(name='source-%d' % idx, target=target)
+            target = OneToOneTarget(name='target-%d' % idx)
+            target.save()
+            source = OneToOneSource(name='source-%d' % idx, target=target)
             source.save()
 
-    def test_foreign_key_retrieve(self):
-        queryset = ForeignKeySource.objects.all()
-        serializer = ForeignKeySourceSerializer(queryset, many=True)
-        expected = [
-            {'id': 1, 'name': 'source-1', 'target': {'id': 1, 'name': 'target-1'}},
-            {'id': 2, 'name': 'source-2', 'target': {'id': 1, 'name': 'target-1'}},
-            {'id': 3, 'name': 'source-3', 'target': {'id': 1, 'name': 'target-1'}},
-        ]
-        self.assertEqual(serializer.data, expected)
-
-    def test_reverse_foreign_key_retrieve(self):
-        queryset = ForeignKeyTarget.objects.all()
-        serializer = ForeignKeyTargetSerializer(queryset, many=True)
-        expected = [
-            {'id': 1, 'name': 'target-1', 'sources': [
-                {'id': 1, 'name': 'source-1', 'target': 1},
-                {'id': 2, 'name': 'source-2', 'target': 1},
-                {'id': 3, 'name': 'source-3', 'target': 1},
-            ]},
-            {'id': 2, 'name': 'target-2', 'sources': [
-            ]}
-        ]
-        self.assertEqual(serializer.data, expected)
-
-
-class NestedNullableForeignKeyTests(TestCase):
-    def setUp(self):
-        target = ForeignKeyTarget(name='target-1')
-        target.save()
-        for idx in range(1, 4):
-            if idx == 3:
-                target = None
-            source = NullableForeignKeySource(name='source-%d' % idx, target=target)
-            source.save()
-
-    def test_foreign_key_retrieve_with_null(self):
-        queryset = NullableForeignKeySource.objects.all()
-        serializer = NullableForeignKeySourceSerializer(queryset, many=True)
-        expected = [
-            {'id': 1, 'name': 'source-1', 'target': {'id': 1, 'name': 'target-1'}},
-            {'id': 2, 'name': 'source-2', 'target': {'id': 1, 'name': 'target-1'}},
-            {'id': 3, 'name': 'source-3', 'target': None},
-        ]
-        self.assertEqual(serializer.data, expected)
-
-
-class NestedNullableOneToOneTests(TestCase):
-    def setUp(self):
-        target = OneToOneTarget(name='target-1')
-        target.save()
-        new_target = OneToOneTarget(name='target-2')
-        new_target.save()
-        source = NullableOneToOneSource(name='source-1', target=target)
-        source.save()
-
-    def test_reverse_foreign_key_retrieve_with_null(self):
+    def test_one_to_one_retrieve(self):
         queryset = OneToOneTarget.objects.all()
-        serializer = NullableOneToOneTargetSerializer(queryset, many=True)
+        serializer = self.Serializer(queryset, many=True)
         expected = [
-            {'id': 1, 'name': 'target-1', 'nullable_source': {'id': 1, 'name': 'source-1', 'target': 1}},
-            {'id': 2, 'name': 'target-2', 'nullable_source': None},
+            {'id': 1, 'name': 'target-1', 'source': {'id': 1, 'name': 'source-1'}},
+            {'id': 2, 'name': 'target-2', 'source': {'id': 2, 'name': 'source-2'}},
+            {'id': 3, 'name': 'target-3', 'source': {'id': 3, 'name': 'source-3'}}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_one_create(self):
+        data = {'id': 4, 'name': 'target-4', 'source': {'id': 4, 'name': 'source-4'}}
+        serializer = self.Serializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'target-4')
+
+        # Ensure (target 4, target_source 4, source 4) are added, and
+        # everything else is as expected.
+        queryset = OneToOneTarget.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'source': {'id': 1, 'name': 'source-1'}},
+            {'id': 2, 'name': 'target-2', 'source': {'id': 2, 'name': 'source-2'}},
+            {'id': 3, 'name': 'target-3', 'source': {'id': 3, 'name': 'source-3'}},
+            {'id': 4, 'name': 'target-4', 'source': {'id': 4, 'name': 'source-4'}}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_one_create_with_invalid_data(self):
+        data = {'id': 4, 'name': 'target-4', 'source': {'id': 4}}
+        serializer = self.Serializer(data=data)
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(serializer.errors, {'source': [{'name': ['This field is required.']}]})
+
+    def test_one_to_one_update(self):
+        data = {'id': 3, 'name': 'target-3-updated', 'source': {'id': 3, 'name': 'source-3-updated'}}
+        instance = OneToOneTarget.objects.get(pk=3)
+        serializer = self.Serializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'target-3-updated')
+
+        # Ensure (target 3, target_source 3, source 3) are updated,
+        # and everything else is as expected.
+        queryset = OneToOneTarget.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'source': {'id': 1, 'name': 'source-1'}},
+            {'id': 2, 'name': 'target-2', 'source': {'id': 2, 'name': 'source-2'}},
+            {'id': 3, 'name': 'target-3-updated', 'source': {'id': 3, 'name': 'source-3-updated'}}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+
+class ForwardNestedOneToOneTests(TestCase):
+    def setUp(self):
+        class OneToOneTargetSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = OneToOneTarget
+                fields = ('id', 'name')
+
+        class OneToOneSourceSerializer(serializers.ModelSerializer):
+            target = OneToOneTargetSerializer()
+
+            class Meta:
+                model = OneToOneSource
+                fields = ('id', 'name', 'target')
+
+        self.Serializer = OneToOneSourceSerializer
+
+        for idx in range(1, 4):
+            target = OneToOneTarget(name='target-%d' % idx)
+            target.save()
+            source = OneToOneSource(name='source-%d' % idx, target=target)
+            source.save()
+
+    def test_one_to_one_retrieve(self):
+        queryset = OneToOneSource.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': {'id': 1, 'name': 'target-1'}},
+            {'id': 2, 'name': 'source-2', 'target': {'id': 2, 'name': 'target-2'}},
+            {'id': 3, 'name': 'source-3', 'target': {'id': 3, 'name': 'target-3'}}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_one_create(self):
+        data = {'id': 4, 'name': 'source-4', 'target': {'id': 4, 'name': 'target-4'}}
+        serializer = self.Serializer(data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'source-4')
+
+        # Ensure (target 4, target_source 4, source 4) are added, and
+        # everything else is as expected.
+        queryset = OneToOneSource.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': {'id': 1, 'name': 'target-1'}},
+            {'id': 2, 'name': 'source-2', 'target': {'id': 2, 'name': 'target-2'}},
+            {'id': 3, 'name': 'source-3', 'target': {'id': 3, 'name': 'target-3'}},
+            {'id': 4, 'name': 'source-4', 'target': {'id': 4, 'name': 'target-4'}}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_one_create_with_invalid_data(self):
+        data = {'id': 4, 'name': 'source-4', 'target': {'id': 4}}
+        serializer = self.Serializer(data=data)
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(serializer.errors, {'target': [{'name': ['This field is required.']}]})
+
+    def test_one_to_one_update(self):
+        data = {'id': 3, 'name': 'source-3-updated', 'target': {'id': 3, 'name': 'target-3-updated'}}
+        instance = OneToOneSource.objects.get(pk=3)
+        serializer = self.Serializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'source-3-updated')
+
+        # Ensure (target 3, target_source 3, source 3) are updated,
+        # and everything else is as expected.
+        queryset = OneToOneSource.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': {'id': 1, 'name': 'target-1'}},
+            {'id': 2, 'name': 'source-2', 'target': {'id': 2, 'name': 'target-2'}},
+            {'id': 3, 'name': 'source-3-updated', 'target': {'id': 3, 'name': 'target-3-updated'}}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_one_update_to_null(self):
+        data = {'id': 3, 'name': 'source-3-updated', 'target': None}
+        instance = OneToOneSource.objects.get(pk=3)
+        serializer = self.Serializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'source-3-updated')
+        self.assertEqual(obj.target, None)
+
+        queryset = OneToOneSource.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'source-1', 'target': {'id': 1, 'name': 'target-1'}},
+            {'id': 2, 'name': 'source-2', 'target': {'id': 2, 'name': 'target-2'}},
+            {'id': 3, 'name': 'source-3-updated', 'target': None}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    # TODO: Nullable 1-1 tests
+    # def test_one_to_one_delete(self):
+    #     data = {'id': 3, 'name': 'target-3', 'target_source': None}
+    #     instance = OneToOneTarget.objects.get(pk=3)
+    #     serializer = self.Serializer(instance, data=data)
+    #     self.assertTrue(serializer.is_valid())
+    #     serializer.save()
+
+    #     # Ensure (target_source 3, source 3) are deleted,
+    #     # and everything else is as expected.
+    #     queryset = OneToOneTarget.objects.all()
+    #     serializer = self.Serializer(queryset)
+    #     expected = [
+    #         {'id': 1, 'name': 'target-1', 'source': {'id': 1, 'name': 'source-1'}},
+    #         {'id': 2, 'name': 'target-2', 'source': {'id': 2, 'name': 'source-2'}},
+    #         {'id': 3, 'name': 'target-3', 'source': None}
+    #     ]
+    #     self.assertEqual(serializer.data, expected)
+
+
+class ReverseNestedOneToManyTests(TestCase):
+    def setUp(self):
+        class OneToManySourceSerializer(serializers.ModelSerializer):
+            class Meta:
+                model = OneToManySource
+                fields = ('id', 'name')
+
+        class OneToManyTargetSerializer(serializers.ModelSerializer):
+            sources = OneToManySourceSerializer(many=True, allow_add_remove=True)
+
+            class Meta:
+                model = OneToManyTarget
+                fields = ('id', 'name', 'sources')
+
+        self.Serializer = OneToManyTargetSerializer
+
+        target = OneToManyTarget(name='target-1')
+        target.save()
+        for idx in range(1, 4):
+            source = OneToManySource(name='source-%d' % idx, target=target)
+            source.save()
+
+    def test_one_to_many_retrieve(self):
+        queryset = OneToManyTarget.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [{'id': 1, 'name': 'source-1'},
+                                                      {'id': 2, 'name': 'source-2'},
+                                                      {'id': 3, 'name': 'source-3'}]},
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_many_create(self):
+        data = {'id': 1, 'name': 'target-1', 'sources': [{'id': 1, 'name': 'source-1'},
+                                                         {'id': 2, 'name': 'source-2'},
+                                                         {'id': 3, 'name': 'source-3'},
+                                                         {'id': 4, 'name': 'source-4'}]}
+        instance = OneToManyTarget.objects.get(pk=1)
+        serializer = self.Serializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'target-1')
+
+        # Ensure source 4 is added, and everything else is as
+        # expected.
+        queryset = OneToManyTarget.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [{'id': 1, 'name': 'source-1'},
+                                                      {'id': 2, 'name': 'source-2'},
+                                                      {'id': 3, 'name': 'source-3'},
+                                                      {'id': 4, 'name': 'source-4'}]}
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_many_create_with_invalid_data(self):
+        data = {'id': 1, 'name': 'target-1', 'sources': [{'id': 1, 'name': 'source-1'},
+                                                         {'id': 2, 'name': 'source-2'},
+                                                         {'id': 3, 'name': 'source-3'},
+                                                         {'id': 4}]}
+        serializer = self.Serializer(data=data)
+        self.assertFalse(serializer.is_valid())
+        self.assertEqual(serializer.errors, {'sources': [{}, {}, {}, {'name': ['This field is required.']}]})
+
+    def test_one_to_many_update(self):
+        data = {'id': 1, 'name': 'target-1-updated', 'sources': [{'id': 1, 'name': 'source-1-updated'},
+                                                                 {'id': 2, 'name': 'source-2'},
+                                                                 {'id': 3, 'name': 'source-3'}]}
+        instance = OneToManyTarget.objects.get(pk=1)
+        serializer = self.Serializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        obj = serializer.save()
+        self.assertEqual(serializer.data, data)
+        self.assertEqual(obj.name, 'target-1-updated')
+
+        # Ensure (target 1, source 1) are updated,
+        # and everything else is as expected.
+        queryset = OneToManyTarget.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1-updated', 'sources': [{'id': 1, 'name': 'source-1-updated'},
+                                                              {'id': 2, 'name': 'source-2'},
+                                                              {'id': 3, 'name': 'source-3'}]}
+
+        ]
+        self.assertEqual(serializer.data, expected)
+
+    def test_one_to_many_delete(self):
+        data = {'id': 1, 'name': 'target-1', 'sources': [{'id': 1, 'name': 'source-1'},
+                                                         {'id': 3, 'name': 'source-3'}]}
+        instance = OneToManyTarget.objects.get(pk=1)
+        serializer = self.Serializer(instance, data=data)
+        self.assertTrue(serializer.is_valid())
+        serializer.save()
+
+        # Ensure source 2 is deleted, and everything else is as
+        # expected.
+        queryset = OneToManyTarget.objects.all()
+        serializer = self.Serializer(queryset, many=True)
+        expected = [
+            {'id': 1, 'name': 'target-1', 'sources': [{'id': 1, 'name': 'source-1'},
+                                                      {'id': 3, 'name': 'source-3'}]}
+
         ]
         self.assertEqual(serializer.data, expected)
diff --git a/rest_framework/tests/test_routers.py b/rest_framework/tests/test_routers.py
index c3597e389..3f456fefd 100644
--- a/rest_framework/tests/test_routers.py
+++ b/rest_framework/tests/test_routers.py
@@ -146,7 +146,7 @@ class TestTrailingSlashRemoved(TestCase):
         self.urls = self.router.urls
 
     def test_urls_can_have_trailing_slash_removed(self):
-        expected = ['^notes$', '^notes/(?P<pk>[^/]+)$']
+        expected = ['^notes$', '^notes/(?P<pk>[^/.]+)$']
         for idx in range(len(expected)):
             self.assertEqual(expected[idx], self.urls[idx].regex.pattern)
 
diff --git a/rest_framework/tests/test_testing.py b/rest_framework/tests/test_testing.py
index 49d45fc29..48b8956b5 100644
--- a/rest_framework/tests/test_testing.py
+++ b/rest_framework/tests/test_testing.py
@@ -17,8 +17,18 @@ def view(request):
     })
 
 
+@api_view(['GET', 'POST'])
+def session_view(request):
+    active_session = request.session.get('active_session', False)
+    request.session['active_session'] = True
+    return Response({
+        'active_session': active_session
+    })
+
+
 urlpatterns = patterns('',
     url(r'^view/$', view),
+    url(r'^session-view/$', session_view),
 )
 
 
@@ -46,6 +56,26 @@ class TestAPITestClient(TestCase):
         response = self.client.get('/view/')
         self.assertEqual(response.data['user'], 'example')
 
+    def test_force_authenticate_with_sessions(self):
+        """
+        Setting `.force_authenticate()` forcibly authenticates each request.
+        """
+        user = User.objects.create_user('example', 'example@example.com')
+        self.client.force_authenticate(user)
+
+        # First request does not yet have an active session
+        response = self.client.get('/session-view/')
+        self.assertEqual(response.data['active_session'], False)
+
+        # Subsequant requests have an active session
+        response = self.client.get('/session-view/')
+        self.assertEqual(response.data['active_session'], True)
+
+        # Force authenticating as `None` should also logout the user session.
+        self.client.force_authenticate(None)
+        response = self.client.get('/session-view/')
+        self.assertEqual(response.data['active_session'], False)
+
     def test_csrf_exempt_by_default(self):
         """
         By default, the test client is CSRF exempt.
diff --git a/rest_framework/throttling.py b/rest_framework/throttling.py
index 65b455930..a946d837f 100644
--- a/rest_framework/throttling.py
+++ b/rest_framework/throttling.py
@@ -2,7 +2,7 @@
 Provides various throttling policies.
 """
 from __future__ import unicode_literals
-from django.core.cache import cache
+from django.core.cache import cache as default_cache
 from django.core.exceptions import ImproperlyConfigured
 from rest_framework.settings import api_settings
 import time
@@ -39,6 +39,7 @@ class SimpleRateThrottle(BaseThrottle):
     Previous request information used for throttling is stored in the cache.
     """
 
+    cache = default_cache
     timer = time.time
     cache_format = 'throtte_%(scope)s_%(ident)s'
     scope = None
@@ -99,7 +100,7 @@ class SimpleRateThrottle(BaseThrottle):
         if self.key is None:
             return True
 
-        self.history = cache.get(self.key, [])
+        self.history = self.cache.get(self.key, [])
         self.now = self.timer()
 
         # Drop any requests from the history which have now passed the
@@ -116,7 +117,7 @@ class SimpleRateThrottle(BaseThrottle):
         into the cache.
         """
         self.history.insert(0, self.now)
-        cache.set(self.key, self.history, self.duration)
+        self.cache.set(self.key, self.history, self.duration)
         return True
 
     def throttle_failure(self):
@@ -151,7 +152,9 @@ class AnonRateThrottle(SimpleRateThrottle):
         if request.user.is_authenticated():
             return None  # Only throttle unauthenticated requests.
 
-        ident = request.META.get('REMOTE_ADDR', None)
+        ident = request.META.get('HTTP_X_FORWARDED_FOR')
+        if ident is None:
+            ident = request.META.get('REMOTE_ADDR')
 
         return self.cache_format % {
             'scope': self.scope,
diff --git a/rest_framework/utils/breadcrumbs.py b/rest_framework/utils/breadcrumbs.py
index 0384faba3..e6690d170 100644
--- a/rest_framework/utils/breadcrumbs.py
+++ b/rest_framework/utils/breadcrumbs.py
@@ -8,8 +8,11 @@ def get_breadcrumbs(url):
     tuple of (name, url).
     """
 
+    from rest_framework.settings import api_settings
     from rest_framework.views import APIView
 
+    view_name_func = api_settings.VIEW_NAME_FUNCTION
+
     def breadcrumbs_recursive(url, breadcrumbs_list, prefix, seen):
         """
         Add tuples of (name, url) to the breadcrumbs list,
@@ -28,8 +31,8 @@ def get_breadcrumbs(url):
                 # Don't list the same view twice in a row.
                 # Probably an optional trailing slash.
                 if not seen or seen[-1] != view:
-                    instance = view.cls()
-                    name = instance.get_view_name()
+                    suffix = getattr(view, 'suffix', None)
+                    name = view_name_func(cls, suffix)
                     breadcrumbs_list.insert(0, (name, prefix + url))
                     seen.append(view)
 
diff --git a/rest_framework/views.py b/rest_framework/views.py
index 727a9f956..4cff04224 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -15,8 +15,14 @@ from rest_framework.settings import api_settings
 from rest_framework.utils import formatting
 
 
-def get_view_name(cls, suffix=None):
-    name = cls.__name__
+def get_view_name(view_cls, suffix=None):
+    """
+    Given a view class, return a textual name to represent the view.
+    This name is used in the browsable API, and in OPTIONS responses.
+
+    This function is the default for the `VIEW_NAME_FUNCTION` setting.
+    """
+    name = view_cls.__name__
     name = formatting.remove_trailing_string(name, 'View')
     name = formatting.remove_trailing_string(name, 'ViewSet')
     name = formatting.camelcase_to_spaces(name)
@@ -25,17 +31,56 @@ def get_view_name(cls, suffix=None):
 
     return name
 
-def get_view_description(cls, html=False):
-    description = cls.__doc__ or ''
+def get_view_description(view_cls, html=False):
+    """
+    Given a view class, return a textual description to represent the view.
+    This name is used in the browsable API, and in OPTIONS responses.
+
+    This function is the default for the `VIEW_DESCRIPTION_FUNCTION` setting.
+    """
+    description = view_cls.__doc__ or ''
     description = formatting.dedent(smart_text(description))
     if html:
         return formatting.markup_description(description)
     return description
 
 
-class APIView(View):
-    settings = api_settings
+def exception_handler(exc):
+    """
+    Returns the response that should be used for any given exception.
 
+    By default we handle the REST framework `APIException`, and also
+    Django's builtin `Http404` and `PermissionDenied` exceptions.
+
+    Any unhandled exceptions may return `None`, which will cause a 500 error
+    to be raised.
+    """
+    if isinstance(exc, exceptions.APIException):
+        headers = {}
+        if getattr(exc, 'auth_header', None):
+            headers['WWW-Authenticate'] = exc.auth_header
+        if getattr(exc, 'wait', None):
+            headers['X-Throttle-Wait-Seconds'] = '%d' % exc.wait
+
+        return Response({'detail': exc.detail},
+                        status=exc.status_code,
+                        headers=headers)
+
+    elif isinstance(exc, Http404):
+        return Response({'detail': 'Not found'},
+                        status=status.HTTP_404_NOT_FOUND)
+
+    elif isinstance(exc, PermissionDenied):
+        return Response({'detail': 'Permission denied'},
+                        status=status.HTTP_403_FORBIDDEN)
+
+    # Note: Unhandled exceptions will raise a 500 error.
+    return None
+
+
+class APIView(View):
+
+    # The following policies may be set at either globally, or per-view.
     renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES
     parser_classes = api_settings.DEFAULT_PARSER_CLASSES
     authentication_classes = api_settings.DEFAULT_AUTHENTICATION_CLASSES
@@ -43,6 +88,9 @@ class APIView(View):
     permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
     content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
 
+    # Allow dependancy injection of other settings to make testing easier.
+    settings = api_settings
+
     @classmethod
     def as_view(cls, **initkwargs):
         """
@@ -133,7 +181,7 @@ class APIView(View):
         Return the view name, as used in OPTIONS responses and in the
         browsable API.
         """
-        func = api_settings.VIEW_NAME_FUNCTION
+        func = self.settings.VIEW_NAME_FUNCTION
         return func(self.__class__, getattr(self, 'suffix', None))
 
     def get_view_description(self, html=False):
@@ -141,7 +189,7 @@ class APIView(View):
         Return some descriptive text for the view, as used in OPTIONS responses
         and in the browsable API.
         """
-        func = api_settings.VIEW_DESCRIPTION_FUNCTION
+        func = self.settings.VIEW_DESCRIPTION_FUNCTION
         return func(self.__class__, html)
 
     # API policy instantiation methods
@@ -303,33 +351,23 @@ class APIView(View):
         Handle any exception that occurs, by returning an appropriate response,
         or re-raising the error.
         """
-        if isinstance(exc, exceptions.Throttled) and exc.wait is not None:
-            # Throttle wait header
-            self.headers['X-Throttle-Wait-Seconds'] = '%d' % exc.wait
-
         if isinstance(exc, (exceptions.NotAuthenticated,
                             exceptions.AuthenticationFailed)):
             # WWW-Authenticate header for 401 responses, else coerce to 403
             auth_header = self.get_authenticate_header(self.request)
 
             if auth_header:
-                self.headers['WWW-Authenticate'] = auth_header
+                exc.auth_header = auth_header
             else:
                 exc.status_code = status.HTTP_403_FORBIDDEN
 
-        if isinstance(exc, exceptions.APIException):
-            return Response({'detail': exc.detail},
-                            status=exc.status_code,
-                            exception=True)
-        elif isinstance(exc, Http404):
-            return Response({'detail': 'Not found'},
-                            status=status.HTTP_404_NOT_FOUND,
-                            exception=True)
-        elif isinstance(exc, PermissionDenied):
-            return Response({'detail': 'Permission denied'},
-                            status=status.HTTP_403_FORBIDDEN,
-                            exception=True)
-        raise
+        response = exception_handler(exc)
+
+        if response is None:
+            raise
+
+        response.exception = True
+        return response
 
     # Note: session based authentication is explicitly CSRF validated,
     # all other authentication is CSRF exempt.