5 files changed, 36 insertions, 13 deletions
diff --git a/guides/source/4_0_release_notes.md b/guides/source/4_0_release_notes.md
index a678dd9d90..9c157ec0b3 100644
--- a/guides/source/4_0_release_notes.md
+++ b/guides/source/4_0_release_notes.md
@@ -3,7 +3,7 @@ Ruby on Rails 4.0 Release Notes
 
 Highlights in Rails 4.0:
 
-* Ruby 1.9.3 only
+* Ruby 2.0 preferred; 1.9.3+ required
 * Strong Parameters
 * Turbolinks
 * Russian Doll Caching
diff --git a/guides/source/engines.md b/guides/source/engines.md
index 459aa8d57e..00939c4ff2 100644
--- a/guides/source/engines.md
+++ b/guides/source/engines.md
@@ -28,7 +28,7 @@ Engines can also be isolated from their host applications. This means that an ap
 
 It's important to keep in mind at all times that the application should **always** take precedence over its engines. An application is the object that has final say in what goes on in the universe (with the universe being the application's environment) where the engine should only be enhancing it, rather than changing it drastically.
 
-To see demonstrations of other engines, check out [Devise](https://github.com/plataformatec/devise), an engine that provides authentication for its parent applications, or [Forem](https://github.com/radar/forem), an engine that provides forum functionality. There's also [Spree](https://github.com/spree/spree) which provides an e-commerce platform, and [RefineryCMS](https://github.com/resolve/refinerycms), a CMS engine.
+To see demonstrations of other engines, check out [Devise](https://github.com/plataformatec/devise), an engine that provides authentication for its parent applications, or [Forem](https://github.com/radar/forem), an engine that provides forum functionality. There's also [Spree](https://github.com/spree/spree) which provides an e-commerce platform, and [RefineryCMS](https://github.com/refinery/refinerycms), a CMS engine.
 
 Finally, engines would not have been possible without the work of James Adam, Piotr Sarnacki, the Rails Core Team, and a number of other people. If you ever meet them, don't forget to say thanks!
 
@@ -57,7 +57,7 @@ The `--full` option tells the generator that you want to create an engine, inclu
     end
     ```
   * A file at `lib/blorgh/engine.rb` which is identical in function to a standard Rails application's `config/application.rb` file:
-  
+
     ```ruby
     module Blorgh
       class Engine < ::Rails::Engine
@@ -72,12 +72,12 @@ The `--mountable` option tells the generator that you want to create a "mountabl
   * A namespaced `ApplicationHelper` stub
   * A layout view template for the engine
   * Namespace isolation to `config/routes.rb`:
-  
+
     ```ruby
     Blorgh::Engine.routes.draw do
     end
     ```
- 
+
   * Namespace isolation to `lib/blorgh/engine.rb`:
 
     ```ruby
@@ -395,7 +395,7 @@ def create
   @post = Post.find(params[:post_id])
   @comment = @post.comments.create(params[:comment])
   flash[:notice] = "Comment has been created!"
-  redirect_to post_path
+  redirect_to posts_path
 end
 ```
 
@@ -650,6 +650,14 @@ self.author = Blorgh.user_class.find_or_create_by(name: author_name)
 
 Resulting in something a little shorter, and more implicit in its behavior. The `user_class` method should always return a `Class` object.
 
+Since we changed the `user_class` method to no longer return a
+`String` but a `Class` we must also modify our `belongs_to` definition
+in the `Blorgh::Post` model:
+
+```ruby
+belongs_to :author, class_name: Blorgh.user_class.to_s
+```
+
 To set this configuration setting within the application, an initializer should be used. By using an initializer, the configuration will be set up before the application starts and calls the engine's models which may depend on this configuration setting existing.
 
 Create a new initializer at `config/initializers/blorgh.rb` inside the application where the `blorgh` engine is installed and put this content in it:
@@ -789,7 +797,7 @@ module Blorgh::Concerns::Models::Post
   extend ActiveSupport::Concern
 
   # 'included do' causes the included code to be evaluated in the
-  # context where it is included (post.rb), rather than be 
+  # context where it is included (post.rb), rather than be
   # executed in the module's context (blorgh/concerns/models/post).
   included do
     attr_accessor :author_name
diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md
index c394f30c38..87f5e43157 100644
--- a/guides/source/getting_started.md
+++ b/guides/source/getting_started.md
@@ -21,7 +21,7 @@ application from scratch. It does not assume that you have any prior experience
 with Rails. However, to get the most out of it, you need to have some
 prerequisites installed:
 
-* The [Ruby](http://www.ruby-lang.org/en/downloads) language version 1.9.3 or higher
+* The [Ruby](http://www.ruby-lang.org/en/downloads) language version 1.9.3 or newer
 * The [RubyGems](http://rubygems.org/) packaging system
     * To learn more about RubyGems, please read the [RubyGems User Guide](http://docs.rubygems.org/read/book/1)
 * A working installation of the [SQLite3 Database](http://www.sqlite.org)
@@ -84,7 +84,7 @@ current version of Ruby installed:
 
 ```bash
 $ ruby -v
-ruby 1.9.3p327
+ruby 1.9.3p385
 ```
 
 To install Rails, use the `gem install` command provided by RubyGems:
diff --git a/guides/source/routing.md b/guides/source/routing.md
index 14f23d4020..4614169653 100644
--- a/guides/source/routing.md
+++ b/guides/source/routing.md
@@ -832,6 +832,19 @@ will recognize incoming paths beginning with `/photos` but route to the `Images`
 
 NOTE: Use `photos_path`, `new_photo_path`, etc. to generate paths for this resource.
 
+For namespaced controllers you can use the directory notation. For example:
+
+```ruby
+resources :user_permissions, controller: 'admin/user_permissions'
+```
+
+This will route to the `Admin::UserPermissions` controller.
+
+NOTE: Only the directory notation is supported. specifying the
+controller with ruby constant notation (eg. `:controller =>
+'Admin::UserPermissions'`) can lead to routing problems and results in
+a warning.
+
 ### Specifying Constraints
 
 You can use the `:constraints` option to specify a required format on the implicit `id`. For example:
diff --git a/guides/source/upgrading_ruby_on_rails.md b/guides/source/upgrading_ruby_on_rails.md
index ea04036663..568767d9de 100644
--- a/guides/source/upgrading_ruby_on_rails.md
+++ b/guides/source/upgrading_ruby_on_rails.md
@@ -16,11 +16,11 @@ The best way to be sure that your application still works after upgrading is to
 
 Rails generally stays close to the latest released Ruby version when it's released:
 
-* Rails 3 and above requires Ruby 1.8.7 or higher. Support for all of the previous Ruby versions has been dropped officially and you should upgrade as early as possible.
-* Rails 3.2.x will be the last branch to support Ruby 1.8.7.
-* Rails 4 will support Ruby 1.9.3 or higher.
+* Rails 3 and above require Ruby 1.8.7 or higher. Support for all of the previous Ruby versions has been dropped officially. You should upgrade as early as possible.
+* Rails 3.2.x is the last branch to support Ruby 1.8.7.
+* Rails 4 prefers Ruby 2.0 and requires 1.9.3 or newer.
 
-TIP: Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump on to 1.9.2 or 1.9.3 for smooth sailing.
+TIP: Ruby 1.8.7 p248 and p249 have marshaling bugs that crash Rails. Ruby Enterprise Edition has these fixed since the release of 1.8.7-2010.02. On the 1.9 front, Ruby 1.9.1 is not usable because it outright segfaults, so if you want to use 1.9.x, jump straight to 1.9.3 for smooth sailing.
 
 Upgrading from Rails 3.2 to Rails 4.0
 -------------------------------------
@@ -82,6 +82,8 @@ becomes
 get 'こんにちは', controller: 'welcome', action: 'index'
 ```
 
+* Rails 4.0 has removed ActionDispatch::BestStandardsSupport middleware, !DOCTYPE html already triggers standards mode per http://msdn.microsoft.com/en-us/library/jj676915(v=vs.85).aspx and ChromeFrame header has been moved to `config.action_dispatch.default_headers`
+
 ### Active Support
 
 Rails 4.0 removes the `j` alias for `ERB::Util#json_escape` since `j` is already used for `ActionView::Helpers::JavaScriptHelper#escape_javascript`.