In order to use CyberDEFs, you'll need a development environment that allows you to call the toolbox and use functions in some manner.

You'll also need access to the Control Manager calls: HiliteControl and TrackControl. (There is little need to call the List Manager or the Text Edit Manager, since most of what these managers do is handled internally by the appropriate CDEF.)

MPW, Think C/Pascal and Code Warrior all appear to work just fine in creating windows, dialogs and palettes utilizing CyberDEFs.

In the case of HyperCard and the new SuperCard 1.7: 
In order to use CyberDEFs, you must be skilled in the making of external windows with a C, Pascal or HyperTalk compiler (like CompileIt!).

IMPORTANT NOTE: CyberDEFs do not work in the context of HyperCard or SuperCard cards. They are only for use in external windows or dialogs.

Although admittedly little testing has been done, Prograph, Lisp, Fortran and the SmallTalks for the Mac should have no problems using CyberDEFs.