In object-oriented programming, a metaclass is a class whose instances are classes. Just as an ordinary class defines the behavior of certain objects, a metaclass defines the behavior of certain classes and their instances. Not all object-oriented programming languages support metaclasses. Among those that do, the extent to which metaclasses can override any given aspect of class behavior varies. Each language has its own metaobject protocol, a set of rules that govern how objects, classes, and metaclasses interact.
Often Namespaces are used as identifiers in Metaclasses, to distinguish different classes.
Derive new object
To generate a new metaclass just right-click on the sourceclass (e.g., the Baseclass) and choose Derive new object.
After this the class´s name can be changed in the bottom window ( Details )