programming (BOS) A C-callable library that implements the

notion of object and which uses Tcl as its interpreter

for interpreted methods (you can have "compiled" methods in

C, and mix compiled and interpreted methods in the same

object, plus lots more). You can subclass and mix in existing

objects using BOS to extend, among other things, the set of

tk widgets. BOS is a class-free object system, also

called a prototype-based object system; it is modelled loosely

on the Self system from Stanford University.