gistfile1.rb

require 'rubygems'
require 'active_support/all'

class MyEngine < Object
  class Configuration
    include ActiveSupport::Configurable
    def self.method_missing(meth, *args)
      self.config.send meth, *args
    end
  end
end

class MyEngine::Configuration
  config.something_else = 'else'
end

MyEngine::Configuration.something = 'something'

puts MyEngine::Configuration.something
puts MyEngine::Configuration.something_else