prototype-rails provides Prototype, Scriptaculous, and RJS for Rails 3.1.
Prototype and Scriptaculous are provided via the asset pipeline and you
do *not* need to copy their files into your application. Rails will get
them from prototype-rails automatically.
You may want to add them to your app/assets/javascripts/application.js:
//= require prototype
//= require prototype_ujs
//= require effects
//= require dragdrop
//= require controls
New applications using this may also want to add
config.action_view.debug_rjs = true
to their config/environments/development.rb.