But the problem here is not the suitability of languages themselves, the problem is the huge undertaking required to build a gui library which can compete with Qt, gtk etc.

Crystal at the very least has good support for binding C so maybe this will be the language which finally produces a modern gui toolkit, but with the move towards web apps its becoming increasingly unlikely.

>But the problem here is not the suitability of languages themselves, the problem is the huge undertaking required to build a gui library which can compete with Qt, gtk etc.

Well, the whole Cocoa/QT/WinForms scope might be huge, but we don't even have good minimal UI libs -- e.g. with just the few basic widgets: buttons, text fields, labels, radio buttons, checkboxes, kind of what HTML forms can do -- and only very limited functionality (e.g. no fancy text formatting in the labels or whatever).

Tons of programs could be GUI-fied with just the above (sort of what Tk does, but decent looking).

Libui, which was on hn a while ago, looks like the basic minimal cross-platform gui library to me. And that's already got bindings to crystal.. I think most developers are searching for something more.

Yep, something exactly like that, with good documentation, and bindings for multiple languages, can go a very long way for lots of apps.

It's a huge undertaking because it's an undefined specification. No one really knows what a cross-platform UI library should look like. How do you follow all of the native app standards automatically? How do you handle updates and distrabution?

Please take a look at the GUI they're designing for Red. It is stupidly powerful and just as easy to use to build everything from simple apps described below to much more complex graphics and works on Windows, OSX, and Linux. They still have a ways to go on several aspects of the language, but it looks really nice.