A technique is described that allows a software client to create at run-time a software object that appears to extend or alter the functionality of an existing software class definition. For example, a decorator factory generates a proxy object that dynamically implements a set of interfaces specified by the software client at runtime. From the perspective of the client, the proxy object is logically a child object of the original existing base object. The child object appears to be enhanced by the methods and attributes defined by the set of interfaces and the methods implemented by the delegate object. However, the proxy object does not have actual parent classes. Instead, an invocation transparently intercepts method invocations from the client to the proxy object and invokes the appropriate method, regardless of whether the method is implemented in the base object, the delegate object, or within the proxy object itself.