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. The commands of two packages combined in one interpreter right from the startup of the program. Other examples include: * ''expect'' - includes Tcl and [Expect] packages * ''expectTk'' - includes Tcl, Tk, and [Expect] packages * ''tcl'' - includes Tcl and [TclX] packages * ''itclsh'' - includes Tcl and [Itcl] packages ...and there are others. ''more to come...''