A CyberDEF is a pre-defined object that can be used by programmers to handle much of the GUI-oriented coding within a Macintosh window, dialog or palette.

Technically, CDEF is an abbreviation for Control DEFinition. This is why, when you see it in the resource fork of an application, its type is "CDEF." These standalone code modules contain all the object code necessary to make a specialized control (i.e., a control that has been instantiated* by a control item) behave reliably and consistently.

FYI: Deep down in the system, there is a CDEF for the System 7 pop-up menus. All the instructions that display the menu, determine which menu to use, and select the item to show once the menu is collapsed are orchestrated by a single CDEF!

So...you're already using CDEFs. Why not use CyberDEFs?

*An abstraction made concrete.