gistfile1.txt

>> require 'some_class'
=> true
>> foo = SomeClass.new
=> #<SomeClass:0x100a23900>
>> foo.doit
SomeClass=> nil

some_class.rb

require 'some_module'
class SomeClass
  include SomeModule
  def doit
    printself
  end
end

some_module.rb

module SomeModule
  def printself
    print self.class
  end
end