anchor.diff:    <% section "Installation" do %>
       If your system has "RubyGems":http://rubygems.org/, then you can install Gerbil by running the following commands:
   
  -      gem install -y gerbil
  +      gem install gerbil
         gerbil -v
   
       Otherwise, follow these instructions:
  
positive.code:     * If you installed Gerbil using RubyGems, then run <pre>gerbil -v</pre> and select the right-most item in the output--that is the path of Gerbil's installation directory.
  
      Inside Gerbil's installation directory, you will see (among other things) the following items:
      * <tt>doc/</tt> - contains the user guide and other documentation.
      ** <tt>gerbil.svg</tt> - the source file of the Gerbil logo.
      ** <tt>guide.erb</tt> - the source file of this user guide.
      * <tt>format/</tt> - contains the predefined set of format specification files (see <%= xref 'SpecFile' %>). If you ever need to install your custom format specification file globally, put it inside this directory.
      <% Gerbil[:format_files].each do |file| %>
      ** <tt><%= File.basename(file) %></tt> - <%= YAML.load_file(file)['desc'] %>
      <% end %>
      * <tt>gerbil</tt> - the main source code of Gerbil.
      * <tt>LICENSE</tt> - the project license and copyright notice.
    <% end %>
  <% end %>
  
  
negative.code: 
    Gerbil is *lighter* and more *flexible* than "DocBook":http://www.docbook.org, "Deplate":http://deplate.sourceforge.net, and "SiSU":http://www.jus.uio.no/sisu/SiSU/ because it is small, fast, and lets you <%= xref "HelloWorld", "define your own custom format" %>. Furthermore, Gerbil is *scriptable* unlike raw text generators such as "AsciiDoc":http://www.methods.co.nz/asciidoc/, "txt2tags":http://txt2tags.sourceforge.net, and "Grutatxt":http://www.triptico.com/software/grutatxt.html because it lets you inject Ruby code directly into your documents for dynamic content generation.
  
    Gerbil is *open-source software* (see <%= xref "License" %>) so feel free to contribute your improvements and discuss your ideas in the <%= mailing_list_link %>. You can obtain the source code from Gerbil's "Darcs":http://darcs.net repository by running the following command:
  
      darcs get <%= source_repo_url %> gerbil
  
    <% note "See the source of this guide" do %>
      Did you know that this user guide was generated by Gerbil? Here is "the source document":guide.erb to prove it!
  