anchor.diff:  
   [source,ruby]
   ----
  -html_doc = Asciidoctor.render(data, :safe => :safe,
  -  :attributes => %w(notitle! anchors imagesdir=./images))
  +html = Asciidoctor.convert(content, :safe => :safe,
  +  :attributes => %w(showtitle anchors imagesdir=./images))
   ----
   
   We then use the global `$window` object provided by Opal to register a listener that inserts the rendered HTML document into the page:
  
positive.code: 
  To build [path]_asciidoctor.js_, you'll need some tools:
  
  * Npm and Node
  * Bower
  * Rake and Bundle
  
  Start by cloning the source from GitHub:
  
   $ git clone git://github.com/asciidoctor/asciidoctor.js
  
  Next, switch to the _asciidoctor.js_ directory and run Npm's `install` command followed by Bower's `install` command:
  
   $ cd asciidoctor.js
   $ npm install
  
negative.code: 
  You're now ready to build asciidoctor.js.
  
  TIP: Opal.js, The Ruby runtime in JavaScript is available in `bower_components/opal/opal/current/opal.min.js`
  
  == Building asciidoctor.js
  
  