diff --git a/Gemfile b/Gemfile
index fc3738e4bdd..976d6f87e79 100644
--- a/Gemfile
+++ b/Gemfile
@@ -97,6 +97,7 @@ gem 'openid-redis-store'
 gem 'omniauth-facebook'
 gem 'omniauth-twitter'
 gem 'omniauth-github'
+gem 'omniauth-oauth2', require: false
 gem 'omniauth-browserid', git: 'https://github.com/callahad/omniauth-browserid.git', branch: 'observer_api'
 gem 'omniauth-cas'
 gem 'oj'
diff --git a/Gemfile.lock b/Gemfile.lock
index 86dc6284cc9..e188624082e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -497,6 +497,7 @@ DEPENDENCIES
   omniauth-cas
   omniauth-facebook
   omniauth-github
+  omniauth-oauth2
   omniauth-openid
   omniauth-twitter
   openid-redis-store
diff --git a/app/assets/javascripts/discourse.js b/app/assets/javascripts/discourse.js
index b947839b381..2881f7224d1 100644
--- a/app/assets/javascripts/discourse.js
+++ b/app/assets/javascripts/discourse.js
@@ -50,8 +50,8 @@ Discourse = Ember.Application.createWithMixins(Discourse.Ajax, {
 
   faviconChanged: function() {
     if(Discourse.User.currentProp('dynamic_favicon')) {
-      $.faviconNotify(
-        Discourse.SiteSettings.favicon_url, this.get('notifyCount')
+      new Favcount(Discourse.SiteSettings.favicon_url).set(
+        this.get('notifyCount')
       );
     }
   }.observes('notifyCount'),
diff --git a/app/assets/javascripts/external/favcount.js b/app/assets/javascripts/external/favcount.js
new file mode 100644
index 00000000000..5ec64d9092d
--- /dev/null
+++ b/app/assets/javascripts/external/favcount.js
@@ -0,0 +1,84 @@
+/*
+ * favcount.js v1.0.1
+ * http://chrishunt.co/favcount
+ * Dynamically updates the favicon with a number.
+ *
+ * Copyright 2013, Chris Hunt
+ * Released under the MIT license
+ */
+
+(function(){
+  function Favcount(icon) {
+    this.icon = icon;
+    this.canvas = document.createElement('canvas');
+  }
+
+  Favcount.prototype.set = function(count) {
+    var self = this,
+        img  = document.createElement('img');
+
+    if (self.canvas.getContext) {
+      img.onload = function() {
+        drawCanvas(self.canvas, img, normalize(count));
+      };
+
+      img.src = this.icon;
+    }
+  }
+
+  function normalize(count) {
+    count = Math.round(count);
+
+    if (isNaN(count) || count < 1) {
+      return '';
+    } else if (count < 10) {
+      return ' ' + count;
+    } else if (count > 99) {
+      return '99';
+    } else {
+      return count;
+    }
+  }
+
+  function drawCanvas(canvas, img, count) {
+    var head = document.getElementsByTagName('head')[0],
+        favicon = document.createElement('link'),
+        multiplier, fontSize, context, xOffset, yOffset;
+
+    favicon.rel = 'icon';
+
+    // Scale the canvas based on favicon size
+    multiplier = img.width / 16;
+    fontSize   = multiplier * 11;
+    xOffset    = multiplier;
+    yOffset    = multiplier * 11;
+
+    canvas.height = canvas.width = img.width;
+
+    context = canvas.getContext('2d');
+    context.drawImage(img, 0, 0);
+    context.font = 'bold ' + fontSize + 'px "helvetica", sans-serif';
+
+    // Draw background for contrast
+    context.fillStyle = '#FFF';
+    context.fillText(count, xOffset, yOffset);
+    context.fillText(count, xOffset + 2, yOffset);
+    context.fillText(count, xOffset, yOffset + 2);
+    context.fillText(count, xOffset + 2, yOffset + 2);
+
+    // Draw count in foreground
+    context.fillStyle = '#000';
+    context.fillText(count, xOffset + 1, yOffset + 1);
+
+    // Replace the favicon
+    favicon.href = canvas.toDataURL('image/png');
+    head.removeChild(document.querySelector('link[rel=icon]'));
+    head.appendChild(favicon);
+  }
+
+  this.Favcount = Favcount;
+}).call(this);
+
+(function(){
+  Favcount.VERSION = '1.0.1';
+}).call(this);
diff --git a/app/assets/javascripts/external/jquery.faviconNotify.js b/app/assets/javascripts/external/jquery.faviconNotify.js
deleted file mode 100644
index 984bd2dd0d3..00000000000
--- a/app/assets/javascripts/external/jquery.faviconNotify.js
+++ /dev/null
@@ -1,53 +0,0 @@
-/**
-* jQuery Favicon Notify
-*
-* Updates the favicon with a number to notify the user of changes.
-*
-* iconUrl: Url of favicon image or icon
-* count:   Integer count to place above favicon
-*
-* $.faviconNotify(iconUrl, count)
-*/
-(function($){
-  $.faviconNotify = function(iconUrl, count){
-    var canvas = canvas || $('<canvas />')[0],
-        img = $('<img />')[0],
-        multiplier, fontSize, context, xOffset, yOffset;
-
-    if (canvas.getContext) {
-           if (count < 1)  { count = '' }
-      else if (count < 10) { count = ' ' + count }
-      else if (count > 99) { count = '99' }
-
-      img.onload = function () {
-        canvas.height = canvas.width = this.width;
-        multiplier = (this.width / 16);
-
-        fontSize = multiplier * 11;
-        xOffset  = multiplier;
-        yOffset  = multiplier * 11;
-
-        context = canvas.getContext('2d');
-        context.drawImage(this, 0, 0);
-        context.font = 'bold ' + fontSize + 'px "helvetica", sans-serif';
-
-        context.fillStyle = '#FFF';
-        context.fillText(count, xOffset, yOffset);
-        context.fillText(count, xOffset + 2, yOffset);
-        context.fillText(count, xOffset, yOffset + 2);
-        context.fillText(count, xOffset + 2, yOffset + 2);
-
-        context.fillStyle = '#000';
-        context.fillText(count, xOffset + 1, yOffset + 1);
-
-        $('link[rel$=icon]').remove();
-        $('head').append(
-          $('<link rel="shortcut icon" type="image/x-icon"/>').attr(
-            'href', canvas.toDataURL('image/png')
-          )
-        );
-      };
-      img.src = iconUrl;
-    }
-  };
-})(jQuery);
diff --git a/app/controllers/users/omniauth_callbacks_controller.rb b/app/controllers/users/omniauth_callbacks_controller.rb
index 0edc93bbf3d..9d9ebb4779b 100644
--- a/app/controllers/users/omniauth_callbacks_controller.rb
+++ b/app/controllers/users/omniauth_callbacks_controller.rb
@@ -29,6 +29,10 @@ class Users::OmniauthCallbacksController < ApplicationController
         create_or_sign_on_user_using_openid request.env["omniauth.auth"]
         found = true
         break
+      elsif p.name == provider && p.type == :oauth2
+        create_or_sign_on_user_using_oauth2 request.env["omniauth.auth"]
+        found = true
+        break
       end
     end
 
@@ -194,6 +198,58 @@ class Users::OmniauthCallbacksController < ApplicationController
 
   end
 
+  def create_or_sign_on_user_using_oauth2(auth_token)
+    oauth2_provider = auth_token[:provider]
+    oauth2_uid = auth_token[:uid]
+    data = auth_token[:info]
+    email = data[:email]
+    name = data[:name]
+
+    oauth2_user_info = Oauth2UserInfo.where(uid: oauth2_uid, provider: oauth2_provider).first
+
+    if oauth2_user_info.blank? && user = User.find_by_email(email)
+      # TODO is only safe if we trust our oauth2 provider to return an email
+      # legitimately owned by our user
+      oauth2_user_info = Oauth2UserInfo.create(uid: oauth2_uid,
+                                               provider: oauth2_provider,
+                                               name: name,
+                                               email: name,
+                                               user: user)
+    end
+
+    authenticated = oauth2_user_info.present?
+
+    if authenticated
+      user = oauth2_user_info.user
+
+      # If we have to approve users
+      if Guardian.new(user).can_access_forum?
+        log_on_user(user)
+        @data = {authenticated: true}
+      else
+        @data = {awaiting_approval: true}
+      end
+    else
+      @data = {
+        email: email,
+        name: User.suggest_name(name),
+        username: UserNameSuggester.suggest(email),
+        email_valid: true ,
+        auth_provider: oauth2_provider
+      }
+
+      session[:authentication] = {
+        oauth2: {
+          provider: oauth2_provider,
+          uid: oauth2_uid,
+        },
+        name: name,
+        email: @data[:email],
+        email_valid: @data[:email_valid]
+      }
+    end
+  end
+
 
   def create_or_sign_on_user_using_openid(auth_token)
 
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 681b4e9fef3..7addd1014fc 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -432,6 +432,16 @@ class UsersController < ApplicationController
           github_user_id: auth[:github_user_id]
         )
       end
+
+      if oauth2_auth?(auth)
+        Oauth2UserInfo.create(
+          uid: auth[:oauth2][:uid],
+          provider: auth[:oauth2][:provider],
+          name: auth[:name],
+          email: auth[:email],
+          user_id: user.id
+        )
+      end
     end
 
     def twitter_auth?(auth)
@@ -448,4 +458,9 @@ class UsersController < ApplicationController
       auth[:github_user_id] && auth[:github_screen_name] &&
       GithubUserInfo.find_by_github_user_id(auth[:github_user_id]).nil?
     end
+
+    def oauth2_auth?(auth)
+      auth[:oauth2].is_a?(Hash) && auth[:oauth2][:provider] && auth[:oauth2][:uid] &&
+      Oauth2UserInfo.where(provider: auth[:oauth2][:provider], uid: auth[:oauth2][:uid]).empty?
+    end
 end
diff --git a/app/models/category.rb b/app/models/category.rb
index 853d94ddfde..942fa06a5aa 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -1,9 +1,17 @@
 class Category < ActiveRecord::Base
   belongs_to :topic, dependent: :destroy
-  belongs_to :topic_only_relative_url,
+  if rails4?
+    belongs_to :topic_only_relative_url,
+    -> { select "id, title, slug" },
+    class_name: "Topic",
+    foreign_key: "topic_id"
+  else
+    belongs_to :topic_only_relative_url,
     select: "id, title, slug",
     class_name: "Topic",
     foreign_key: "topic_id"
+  end
+
   belongs_to :user
 
   has_many :topics
diff --git a/app/models/oauth2_user_info.rb b/app/models/oauth2_user_info.rb
new file mode 100644
index 00000000000..048f05b781c
--- /dev/null
+++ b/app/models/oauth2_user_info.rb
@@ -0,0 +1,4 @@
+class Oauth2UserInfo < ActiveRecord::Base
+  belongs_to :user
+
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index b014563c42f..b9cb05f5961 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -34,6 +34,7 @@ class User < ActiveRecord::Base
   has_one :twitter_user_info, dependent: :destroy
   has_one :github_user_info, dependent: :destroy
   has_one :cas_user_info, dependent: :destroy
+  has_one :oauth2_user_info, dependent: :destroy
   belongs_to :approved_by, class_name: 'User'
 
   has_many :group_users
diff --git a/config/initializers/omniauth.rb b/config/initializers/omniauth.rb
index 91c9a5cb005..d6d2b2cad52 100644
--- a/config/initializers/omniauth.rb
+++ b/config/initializers/omniauth.rb
@@ -25,6 +25,14 @@ Rails.application.config.middleware.use OmniAuth::Builder do
         :store => OpenID::Store::Redis.new($redis),
         :require => "omniauth-openid"
       }.merge(p.options)
+    elsif p.type == :oauth2
+      provider :oauth2,
+               p.options[:client_id],
+               p.options[:client_secret],
+               {
+                 :name => p.name,
+                 :require => "omniauth-oauth2"
+               }.merge(p.options)
     end
   end
 
diff --git a/db/migrate/20130816024250_create_oauth2_user_infos.rb b/db/migrate/20130816024250_create_oauth2_user_infos.rb
new file mode 100644
index 00000000000..d5a392fb61d
--- /dev/null
+++ b/db/migrate/20130816024250_create_oauth2_user_infos.rb
@@ -0,0 +1,14 @@
+class CreateOauth2UserInfos < ActiveRecord::Migration
+  def change
+    create_table :oauth2_user_infos do |t|
+      t.integer :user_id, null: false
+      t.string :uid, null: false
+      t.string :provider, null: false
+      t.string :email
+      t.string :name
+      t.timestamps
+    end
+
+    add_index :oauth2_user_infos, [:uid, :provider], unique: true
+  end
+end
diff --git a/lib/freedom_patches/active_record_relation.rb b/lib/freedom_patches/active_record_relation.rb
new file mode 100644
index 00000000000..ab5cb77eafa
--- /dev/null
+++ b/lib/freedom_patches/active_record_relation.rb
@@ -0,0 +1,14 @@
+unless Rails.version =~ /^4/
+  module ActiveRecord
+    class Relation
+      # Patch Rails 3 ActiveRecord::Relation to noop on Rails 4 references
+      # thereby getting code that works for rails 3 and 4 without
+      # deprecation warnings
+
+      def references(*args)
+        self
+      end
+
+    end
+  end
+end
diff --git a/lib/search.rb b/lib/search.rb
index 3d6b7001660..0d356323425 100644
--- a/lib/search.rb
+++ b/lib/search.rb
@@ -118,9 +118,7 @@ class Search
                            .order("topics_month DESC")
                            .secured(@guardian)
                            .limit(@limit)
-      if rails4?
-        categories = categories.references(:category_search_data)
-      end
+                           .references(:category_search_data)
 
       categories.each do |c|
         @results.add_result(SearchResult.from_category(c))
@@ -133,9 +131,7 @@ class Search
                   .order("CASE WHEN username_lower = '#{@original_term.downcase}' THEN 0 ELSE 1 END")
                   .order("last_posted_at DESC")
                   .limit(@limit)
-      if rails4?
-        users = users.references(:user_search_data)
-      end
+                  .references(:user_search_data)
 
       users.each do |u|
         @results.add_result(SearchResult.from_user(u))
@@ -148,10 +144,7 @@ class Search
                   .where("topics.deleted_at" => nil)
                   .where("topics.visible")
                   .where("topics.archetype <> ?", Archetype.private_message)
-
-      if rails4?
-        posts = posts.references(:post_search_data, {:topic => :category})
-      end
+                  .references(:post_search_data, {:topic => :category})
 
       # If we have a search context, prioritize those posts first
       if @search_context.present?
diff --git a/lib/topic_query.rb b/lib/topic_query.rb
index 58d6abef0fc..571f49fcd6e 100644
--- a/lib/topic_query.rb
+++ b/lib/topic_query.rb
@@ -212,23 +212,23 @@ class TopicQuery
       end
 
       result = result.listable_topics.includes(category: :topic_only_relative_url)
-      result = result.where('categories.name is null or categories.name <> ?', options[:exclude_category]) if options[:exclude_category]
-      result = result.where('categories.name = ?', options[:only_category]) if options[:only_category]
+      result = result.where('categories.name is null or categories.name <> ?', options[:exclude_category]).references(:categories) if options[:exclude_category]
+      result = result.where('categories.name = ?', options[:only_category]).references(:categories) if options[:only_category]
       result = result.limit(options[:per_page]) unless options[:limit] == false
       result = result.visible if options[:visible] || @user.nil? || @user.regular?
-      result = result.where('topics.id <> ?', options[:except_topic_id]) if options[:except_topic_id]
+      result = result.where('topics.id <> ?', options[:except_topic_id]).references(:topics) if options[:except_topic_id]
       result = result.offset(options[:page].to_i * options[:per_page]) if options[:page]
 
       if options[:topic_ids]
-        result = result.where('topics.id in (?)', options[:topic_ids])
+        result = result.where('topics.id in (?)', options[:topic_ids]).references(:topics)
       end
 
       unless @user && @user.moderator?
         category_ids = @user.secure_category_ids if @user
         if category_ids.present?
-          result = result.where('categories.read_restricted IS NULL OR categories.read_restricted = ? OR categories.id IN (?)', false, category_ids)
+          result = result.where('categories.read_restricted IS NULL OR categories.read_restricted = ? OR categories.id IN (?)', false, category_ids).references(:categories)
         else
-          result = result.where('categories.read_restricted IS NULL OR categories.read_restricted = ?', false)
+          result = result.where('categories.read_restricted IS NULL OR categories.read_restricted = ?', false).references(:categories)
         end
       end
 
diff --git a/lib/trashable.rb b/lib/trashable.rb
index ef6fd724373..5d0e74b2850 100644
--- a/lib/trashable.rb
+++ b/lib/trashable.rb
@@ -2,7 +2,7 @@ module Trashable
   extend ActiveSupport::Concern
 
   included do
-    default_scope where(with_deleted_scope_sql)
+    default_scope { where(with_deleted_scope_sql) }
 
     # scope unscoped does not work
     belongs_to :deleted_by, class_name: 'User'
@@ -15,11 +15,8 @@ module Trashable
       #
       # with this in place Post.limit(10).with_deleted, will work as expected
       #
-      if rails4?
-        scope = self.all.with_default_scope
-      else
-        scope = self.scoped.with_default_scope
-      end
+      scope = rails4? ? self.all.with_default_scope : self.scoped.with_default_scope
+
       scope.where_values.delete(with_deleted_scope_sql)
       scope
     end
diff --git a/plugins/.gitkeep b/plugins/.gitkeep
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/spec/controllers/omniauth_callbacks_controller_spec.rb b/spec/controllers/omniauth_callbacks_controller_spec.rb
index a7c41f18f9c..966fbef70b0 100644
--- a/spec/controllers/omniauth_callbacks_controller_spec.rb
+++ b/spec/controllers/omniauth_callbacks_controller_spec.rb
@@ -164,4 +164,25 @@ describe Users::OmniauthCallbacksController do
 
   end
 
+  describe 'oauth2' do
+    before do
+      Discourse.stubs(:auth_providers).returns([stub(name: 'my_oauth2_provider', type: :oauth2)])
+      request.env["omniauth.auth"] = { uid: 'my-uid', provider: 'my-oauth-provider-domain.net', info: {email: 'eviltrout@made.up.email', name: 'Chatanooga'}}
+    end
+
+    describe "#create_or_sign_on_user_using_oauth2" do
+      context "User already exists" do
+        before do
+          User.stubs(:find_by_email).returns(Fabricate(:user))
+        end
+
+        it "should create an OauthUserInfo" do
+          expect {
+            post :complete, provider: 'my_oauth2_provider'
+          }.to change { Oauth2UserInfo.count }.by(1)
+        end
+      end
+    end
+  end
+
 end