Hi class A def instanceMethod end def A.classMethod end end a = A.new def a.objectMethod end Ruby uses Singleton class for the object a that contains the message table with objectMethod in it. Similarly for classMethod. Is use of singleton class a specification of ruby or it is implementation choice? for example, we can define internal structure for objects in such a way that it contains message table. regards, rolo "Best part of Ruby is its mailing list which Python does not have"