7 files changed, 39 insertions, 9 deletions

diff --git a/guides/source/4_0_release_notes.md b/guides/source/4_0_release_notes.md
index 006d0cda92..8be7a86d20 100644
--- a/guides/source/4_0_release_notes.md
+++ b/guides/source/4_0_release_notes.md
@@ -68,19 +68,19 @@ Major Features
  * **Strong parameters** ([commit](https://github.com/rails/rails/commit/a8f6d5c6450a7fe058348a7f10a908352bb6c7fc)) - Only allow whitelisted parameters to update model objects (`params.permit(:title, :text)`).
  * **Routing concerns** ([commit](https://github.com/rails/rails/commit/0dd24728a088fcb4ae616bb5d62734aca5276b1b)) - In the routing DSL, factor out common subroutes (`comments` from `/posts/1/comments` and `/videos/1/comments`).
  * **ActionController::Live** ([commit](https://github.com/rails/rails/commit/af0a9f9eefaee3a8120cfd8d05cbc431af376da3)) - Stream JSON with `response.stream`.
- * **Declarative ETags** ([commit](https://github.com/rails/rails/commit/ed5c938fa36995f06d4917d9543ba78ed506bb8d)) - Set ETag and Last-Modified headers using `etag` and `fresh_when`.
+ * **Declarative ETags** ([commit](https://github.com/rails/rails/commit/ed5c938fa36995f06d4917d9543ba78ed506bb8d)) - Add controller-level etag additions that will be part of the action etag computation
  * **[Russian doll caching](http://37signals.com/svn/posts/3113-how-key-based-cache-expiration-works)** ([commit](https://github.com/rails/rails/commit/4154bf012d2bec2aae79e4a49aa94a70d3e91d49)) - Cache nested fragments of views. Each fragment expires based on a set of dependencies (a cache key). The cache key is usually a template version number and a model object.
  * **Turbolinks** ([commit](https://github.com/rails/rails/commit/e35d8b18d0649c0ecc58f6b73df6b3c8d0c6bb74)) - Serve only one initial HTML page. When the user navigates to another page, use pushState to update the URL and use AJAX to update the title and body.
- * **Decouple ActionView from ActionController** ([commit](https://github.com/rails/rails/commit/78b0934dd1bb84e8f093fb8ef95ca99b297b51cd)) - ActionView is moved outside of ActionPack.
+ * **Decouple ActionView from ActionController** ([commit](https://github.com/rails/rails/commit/78b0934dd1bb84e8f093fb8ef95ca99b297b51cd)) - ActionView was decoupled from ActionPack and will be moved to a separated gem in Rails 4.1.
  * **Do not depend on ActiveModel** ([commit](https://github.com/rails/rails/commit/166dbaa7526a96fdf046f093f25b0a134b277a68)) - ActionPack no longer depends on ActiveModel.
 
 ### General
 
- * **ActiveModel::Model** ([commit](https://github.com/rails/rails/commit/3b822e91d1a6c4eab0064989bbd07aae3a6d0d08)) - `ActiveModel::Model` is extracted from ActiveRecord. `ActiveModel::Model` provides validations and `form_for` for normal Ruby objects.
+ * **ActiveModel::Model** ([commit](https://github.com/rails/rails/commit/3b822e91d1a6c4eab0064989bbd07aae3a6d0d08)) - `ActiveModel::Model`, a mixin to make normal Ruby objects to work with ActionPack out of box (ex. for `form_for`)
  * **New scope API** ([commit](https://github.com/rails/rails/commit/50cbc03d18c5984347965a94027879623fc44cce)) - Scopes must always use callables.
  * **Schema cache dump** ([commit](https://github.com/rails/rails/commit/5ca4fc95818047108e69e22d200e7a4a22969477)) - To improve Rails boot time, instead of loading the schema directly from the database, load the schema from a dump file.
  * **Support for specifying transaction isolation level** ([commit](https://github.com/rails/rails/commit/392eeecc11a291e406db927a18b75f41b2658253)) - Choose whether repeatable reads or improved performance (less locking) is more important.
- * **Dalli** ([commit](https://github.com/rails/rails/commit/82663306f428a5bbc90c511458432afb26d2f238)) - For the memcache session store, use the Dalli memcache client.
+ * **Dalli** ([commit](https://github.com/rails/rails/commit/82663306f428a5bbc90c511458432afb26d2f238)) - Use Dalli memcache client for the memcache store.
  * **Notifications start & finish** ([commit](https://github.com/rails/rails/commit/f08f8750a512f741acb004d0cebe210c5f949f28)) - Active Support instrumentation reports start and finish notifications to subscribers.
  * **Thread safe by default** ([commit](https://github.com/rails/rails/commit/5d416b907864d99af55ebaa400fff217e17570cd)) - Rails can run in threaded app servers without additional configuration. Note: Check that the gems you are using are threadsafe.
  * **PATCH verb** ([commit](https://github.com/rails/rails/commit/eed9f2539e3ab5a68e798802f464b8e4e95e619e)) - In Rails, PATCH replaces PUT. PATCH is used for partial updates of resources.
diff --git a/guides/source/_welcome.html.erb b/guides/source/_welcome.html.erb
index 9210c40c17..0a0a958e30 100644
--- a/guides/source/_welcome.html.erb
+++ b/guides/source/_welcome.html.erb
@@ -15,7 +15,7 @@
 </p>
 <% end %>
 <p>
-  The guides for Rails 3.2.x are available at <a href="http://guides.rubyonrails.org/v3.2.13/">http://guides.rubyonrails.org/v3.2.13/</a>.
+  The guides for Rails 3.2.x are available at <a href="http://guides.rubyonrails.org/v3.2.14/">http://guides.rubyonrails.org/v3.2.14/</a>.
 </p>
 <p>
   The guides for Rails 2.3.x are available at <a href="http://guides.rubyonrails.org/v2.3.11/">http://guides.rubyonrails.org/v2.3.11/</a>.
diff --git a/guides/source/action_mailer_basics.md b/guides/source/action_mailer_basics.md
index 87a08e8661..bf34799eb3 100644
--- a/guides/source/action_mailer_basics.md
+++ b/guides/source/action_mailer_basics.md
@@ -378,7 +378,7 @@ Just like with controller views, use `yield` to render the view inside the
 layout.
 
 You can also pass in a `layout: 'layout_name'` option to the render call inside
-the format block to specify different layouts for different actions:
+the format block to specify different layouts for different formats:
 
 ```ruby
 class UserMailer < ActionMailer::Base
diff --git a/guides/source/command_line.md b/guides/source/command_line.md
index 911c832952..5f98326c57 100644
--- a/guides/source/command_line.md
+++ b/guides/source/command_line.md
@@ -387,7 +387,7 @@ Active Record version     4.0.0
 Action Pack version       4.0.0
 Action Mailer version     4.0.0
 Active Support version    4.0.0
-Middleware                Rack::Sendfile, ActionDispatch::Static, Rack::Lock, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::RemoteIp, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::Migration::CheckPending, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::EncryptedCookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, Rack::Head, Rack::ConditionalGet, Rack::ETag
+Middleware                Rack::Sendfile, ActionDispatch::Static, Rack::Lock, #<ActiveSupport::Cache::Strategy::LocalCache::Middleware:0x007ffd131a7c88>, Rack::Runtime, Rack::MethodOverride, ActionDispatch::RequestId, Rails::Rack::Logger, ActionDispatch::ShowExceptions, ActionDispatch::DebugExceptions, ActionDispatch::RemoteIp, ActionDispatch::Reloader, ActionDispatch::Callbacks, ActiveRecord::Migration::CheckPending, ActiveRecord::ConnectionAdapters::ConnectionManagement, ActiveRecord::QueryCache, ActionDispatch::Cookies, ActionDispatch::Session::EncryptedCookieStore, ActionDispatch::Flash, ActionDispatch::ParamsParser, Rack::Head, Rack::ConditionalGet, Rack::ETag
 Application root          /home/foobar/commandsapp
 Environment               development
 Database adapter          sqlite3
diff --git a/guides/source/contributing_to_ruby_on_rails.md b/guides/source/contributing_to_ruby_on_rails.md
index 24e16ecd40..2f8a178376 100644
--- a/guides/source/contributing_to_ruby_on_rails.md
+++ b/guides/source/contributing_to_ruby_on_rails.md
@@ -264,7 +264,7 @@ The CHANGELOG is an important part of every release. It keeps the list of change
 
 You should add an entry to the CHANGELOG of the framework that you modified if you're adding or removing a feature, committing a bug fix or adding deprecation notices. Refactorings and documentation changes generally should not go to the CHANGELOG.
 
-A CHANGELOG entry should summarize what was changed and should end with author's name. You can use multiple lines if you need more space and you can attach code examples indented with 4 spaces. If a change is related to a specific issue, you should attach issue's number. Here is an example CHANGELOG entry:
+A CHANGELOG entry should summarize what was changed and should end with author's name and it should go on top of a CHANGELOG. You can use multiple lines if you need more space and you can attach code examples indented with 4 spaces. If a change is related to a specific issue, you should attach issue's number. Here is an example CHANGELOG entry:
 
 ```
 *   Summary of a change that briefly describes what was changed. You can use multiple
diff --git a/guides/source/debugging_rails_applications.md b/guides/source/debugging_rails_applications.md
index 77a2dd4b18..50ee934b87 100644
--- a/guides/source/debugging_rails_applications.md
+++ b/guides/source/debugging_rails_applications.md
@@ -209,6 +209,37 @@ logger.tagged("BCX", "Jason") { logger.info "Stuff" }                   # Logs "
 logger.tagged("BCX") { logger.tagged("Jason") { logger.info "Stuff" } } # Logs "[BCX] [Jason] Stuff"
 ```
 
+### Impact of Logs on Performance
+Logging will always have a small impact on performance of your rails app, 
+        particularly when logging to disk.However, there are a few subtleties:
+
+Using the `:debug` level will have a greater performance penalty than `:fatal`,
+      as a far greater number of strings are being evaluated and written to the
+      log output (e.g. disk).
+
+Another potential pitfall is that if you have many calls to `Logger` like this
+      in your code:
+
+```ruby
+logger.debug "Person attributes hash: #{@person.attributes.inspect}"
+```
+
+In the above example, There will be a performance impact even if the allowed 
+output level doesn't include debug. The reason is that Ruby has to evaluate 
+these strings, which includes instantiating the somewhat heavy `String` object 
+and interpolating the variables, and which takes time.
+Therefore, it's recommended to pass blocks to the logger methods, as these are 
+only evaluated if the output level is the same or included in the allowed level 
+(i.e. lazy loading). The same code rewritten would be:
+
+```ruby
+logger.debug {"Person attibutes hash: #{@person.attributes.inspect}"}
+```
+
+The contents of the block, and therefore the string interpolation, is only 
+evaluated if debug is enabled. This performance savings is only really 
+noticeable with large amounts of logging, but it's a good practice to employ.
+
 Debugging with the `debugger` gem
 ---------------------------------
 
diff --git a/guides/source/rails_on_rack.md b/guides/source/rails_on_rack.md
index 3becaccb0a..642c70fd9d 100644
--- a/guides/source/rails_on_rack.md
+++ b/guides/source/rails_on_rack.md
@@ -5,7 +5,6 @@ This guide covers Rails integration with Rack and interfacing with other Rack co
 
 After reading this guide, you will know:
 
-* How to create Rails Metal applications.
 * How to use Rack Middlewares in your Rails applications.
 * Action Pack's internal Middleware stack.
 * How to define a custom Middleware stack.