The word icon can have several meanings within the computing community.
For instance, an icon can be a graphical image used within a GUI application to represent some action to take. [add in wiki references to dealing with icons here...]
The BWidget toolkit supports toolbars with icons very nicely.
You can get an excellent collection of beautiful icons, complete with the supporting software to integrate them into your Tk application, from Adrian Davis' Tk ICONS project.
Icon [L1 ] is a programming language with a long and rich history, although it is even more obscure (Since when is Tcl obscure? -FW; It's a comparitive statement. Think of how many books about Tcl have been published versus books about Java or C and C++. Would you not say that Tcl is more obscure than those languages? It's a relative statement. -- escargo; true -FW) than tcl.
Also, see About Tcl and popularity
There are several points of similarity between the two languages, along with many more differences.
The data structures are implemented in a way that allows a substantial amount of polymophism. The syntax for interating through all the values in a set, or all the elements in a list, or even all the characters in a string is pretty much the same.
Some of the differences are equally significant.
escargo 10/28-30/2002