Metaclasses are classes that are subclasses of the class of classes. Supported by [TclOO] and [XOTcl]. Can be used to do really quite fundamental changes to the way classes work. [LV] weird - normally, I would think of a '''meta''' class as being something ''above'' (and outside) something else, handling information about the something else. So, what kinds of ''really quite fundamental changes'' can be done with metaclasses in tcloo and xotcl? And are there similar concepts in other tcl based object oriented extensions? ---- !!!!!! %| [Category Object Orientation] |% !!!!!!