application.html.erb

# application.html.erb
<%= stylesheet_link_tag    "vendor",      :media => "all" %>
<%= stylesheet_link_tag    "application", :media => "all" %>
<%= javascript_include_tag "vendor" %>
<%= javascript_include_tag "application" %>

fast_application.html.erb

# application.html.erb
<%= stylesheet_link_tag    "vendor",      :media => "all", :debug => false %>
<%= stylesheet_link_tag    "application", :media => "all" %>
<%= javascript_include_tag "vendor",      :debug => false %>
<%= javascript_include_tag "application" %>

production.rb

# config/environments/production.rb
SlowAssets::Application.configure do
  config.assets.precompile += %w( vendor.js vendor.css )
  # ...
end

rails_g_controller

rails g controller slow index
      create  app/controllers/slow_controller.rb
       route  get "slow/index"
       ...

rails_new

C:\Projects\Ruby>rails new slow-assets
      create
      create  README.rdoc
      create  Rakefile
      ...

rails_start

cd slow-assets
rails s
=> Booting WEBrick
=> Rails 3.2.11 application starting in development on http://0.0.0.0:3000

slow_it

# Gemfile
gem 'bootstrap-sass'
gem 'jquery-ui-rails'

# application.js
//= require jquery.ui.all
//= require bootstrap

# application.css
@import "bootstrap";
@import "bootstrap-responsive";

# bundle install and restart the server

split_assets

# application.js
//= require_tree .

# vendor/assets/javascripts/vendor.js
//= require jquery
//= require jquery_ujs
//= require jquery.ui.all
//= require bootstrap

# application.css
/*
*= require_self
*= require_tree .
*/

# vendor/assets/stylesheets/vendor.css
@import "bootstrap";
@import "bootstrap-responsive";