[jrapdx3]

I concur that TclTk is enormously versatile and productive. I've always regarded Tcl as a Lisp-like language. Tcl and Lisp share characteristics like homoiconicity that enable benefits you describe.

Tcl isn't as widely known and used as it deserves to be. I think that's in part due to its syntax being sufficiently different from "mainstream" languages. The learning curve isn't particularly steep, but enough so that developers question whether it's worth the effort to go there.

FWIW Tcl 9.0 has recently been released. The language has been enriched with sophisticated object-oriented capabilities, coroutines, full math tower, etc. It's also rather easy to write extensions in C.

Anyway, the GUI toolkit (Tk) has been "borrowed" by many other languages (e.g., Python's tkinter), so quite a few programmers use TclTk, know it not.