anchor.diff:  end
   ```
   
  -You can fork the finished code for it on [GitHub](https://github.com/BuildYourOwnSinatra/raw-rack) too.
  -
   ## The Structure of this Book
   
  -First we learn Rack; the API ruby frameworks use to communicate with servers. We will build rack middleware, raw rack apps, and we will learn how to configure, boot, mix and match our Rack apps. We will cover everything from call to Rack::Builder stacks.
  +First we will learn Rack; the API ruby frameworks use to communicate with servers. We will build rack middleware, raw rack apps, and we will learn how to configure, boot, mix and match our Rack apps. We will cover everything from `call()` to Rack::Builder stacks.
   
   Then will dive into Rack's request and responses. We will learn how Rack parses requests and how we can modify it with our own data. We will learn how Sinatra::Request and Sinatra::Response merely extend Rack::Request and Rack::Response.
   
   We will build our own raw MVC app on rack and in the process learn the patterns that Ruby frameworks rest on. We will construct a simple router, build Rails like controllers, Sinatra like route blocks and helpers.
   
  -And finally we will bring this all together into a finished framework. A fast minimal framework with a powerful router, flexible structure, and helpers as modules.
  +We will bring this all together into a finished framework. A fast, minimal framework with a powerful router, flexible structure, and helpers as modules.
   
   ## Commits, Notes, Warnings and Tips
   
  -There will be a lot of code samples in this book. They will look like this:
  +There will be code samples in this book. They will look like this:
   
   ```ruby
   class Cats
  
positive.code: end
  ```
  
  At important points in the book there will be links to GitHub commits or branches. You can checkout this commit and keep your progress in sync with the book. They look like this:
  
  <%= commit    'yahweh/universe', '1',      'The Beginning of Everything. A commit Link' %>
  <%= gh_branch 'yahweh/universe', 'master', 'The Beginning of Everything. A branch link' %>
  
negative.code: end
  ```
  
  And we will build an entire mvc app on Rack without any framework. It will look like this:
  
  ```ruby
  class TasksController
  