I would add note that TCL has a very comprehensive testing suite which makes it very easy to add test units.

https://wiki.tcl-lang.org/page/tcltest

Off-topic and nitpick: I just wish people wrote it as Tcl. When I say it out loud, I do say TCL, but in writing it is Tcl.

It's a fair point. I agree. TCL is now a known TV brand. My iPhone auto corrects it to TCL in capitals.

Yeah, no worries. I tell people the same when they say ADA instead of Ada. :D