Little example using const_missing, after reading Chap3 of Rebuilding Rails, this is how rails works.

bobo.rb

class Object
  def self.const_missing c
    STDERR.puts "Missing constant: #{c.inspect}"
  end
end

class Bobo < Object
  def hello
    puts "Hi Bobo!"
  end
end

if __FILE__ == $0
  Bobo.new.hello
  Jajaja
  Meeee
end