[incr Widgets] is an object-oriented mega-widget set that extends
Tcl/Tk and is based on [incr Tcl] and [incr Tk]. This set of
mega-widgets delivers many new, general purpose widgets like option
menus, comboboxes, selection boxes, and various dialogs whose
counterparts are found in Motif and Windows. Since [incr Widgets] is
based on the [incr Tk] extension, the Tk framework of configuration
options, widget commands, and default bindings is maintained. In other
words, each [incr Widgets] mega-widget seamlessly blends with the
standard Tk widgets. They look, act, and feel like Tk widgets. In
addition, all [incr Widgets] mega-widgets are object oriented and may
themselves be extended, using either inheritance or composition.