Description:

[incr Tcl] provides the extra language support needed to build large
Tcl/Tk applications. It introduces the notion of objects, which act as
building blocks for an application. Each object is a bag of data with
a set of procedures or "methods" that are used to manipulate it.
Objects are organized into "classes" with identical characteristics,
and classes can inherit functionality from one another. This
object-oriented paradigm adds another level of organization on top of
the basic variable/procedure elements, and the resulting code is
easier to understand and maintain.