[incr Tk] OOP extension for Tk - run-time files

 [incr Tk] (or itk) combines the object-oriented power of [incr Tcl]
 with the popular Tk graphical toolkit to create a framework for
 creating mega-widgets. One such set of mega-widgets is provided by
 the iwidgets package.
 .
 This package contains everything you need to run itk scripts and
 itk-enabled apps.