Provided are a method, system, and program for invoking methods between computer languages. A plurality of subclasses of a class in a first computer language are instantiated and a plurality of subclasses of a class in a second computer language are instantiated, wherein methods in the subclasses in the second computer language implement functionality of methods in the subclasses in the first computer language. A call is received from an application in the first computer language to one method in the subclasses of the first computer language, wherein the call to the method in the subclass of the first computer language invokes a corresponding method in the subclasses of the second computer language that implements the functionality of the called method in the first computer language.