C programs of a particular type are known
as ''big wish'' programs.  They have this
name because of their similarity to the
[wish] program that is part of Tk.

Unless you are completely new to Tcl/Tk,
you are familiar with the program [tclsh].
With [tclsh] you can interactively enter
Tcl commands and see the results of their
evaluation.  Or you can name a script file
for [tclsh] to evaluate.  The Tcl interpreter
within [tclsh] starts out with all the
built-in command provided by the Tcl package.

The program [wish] is quite similar to [tclsh].
The primary difference is that the Tcl interpreter
within [wish] starts out with all the built-in
commands of both the Tcl and Tk packages.

''more to come...''