This is more or less a TCL version of Node's Express.

I'm not necessarily advocating for that... but what on earth does anyone's choice of server-side framework have to do with the "user-friendliness" or "familiarity" of the client-side UX?

You can serve up a bleeding edge Vue.js app from a PHP backend, or you could serve up a bowl of jQuery spaghetti from Rust or whatever new language comes out next week. These matters can sometimes be tangentially related, but are largely orthogonal.

I'm probably misreading this article. I've always known TCL as the quick-and-dirty user interface of choice. I guess that's not the focus here.

I honestly doubt you clicked the link at all before commenting, and likewise doubt that you've actually had any first-hand exposure to Tcl in the past.

You SEEM to be referencing the "Tk" portion of Tcl/Tk. Tk is the desktop GUI framework that comes with most distributions of Tcl. But it has no apparent relevance to this or any other Tcl-based web framework.

This is kinda like dismissing a Java server-side web framework because Swing is ugly, or dismissing C# on the web because you don't like WPF.

Okay, happy to admit when I'm not fully informed, and this is one of those times. I have interacted with TCL/TK and have made small programs with it, but I have not used TCL directly in the past. In fact, did not even realize TCL was a full language. When I read this article, given my background with TCL/TK, I understood it to be a web framework using a weird desktop GUI... which would be quite odd.

Yes, when I did something like that nearly 20 years ago it was quite odd! But turned out to be terribly useful for us at the time. (Google 'proxytk' if you're curious)