I hope that Crystal gets some kind of “Crystal-native” GUI support, ideally Linux + Windows.
I don’t think an IDE/drag’n’drop is important — if the GUI library is there, people can use it to write an IDE or GUI designer.
Nim nim-lang.org (a compiled Python-like language) has a Nim-native GUI Linux (Gtk) + Windows (win32): NiGui (search github.com for NiGui) which shows it can be done (< 3000 LOC). However, it is very bare bones and incomplete. A similar attempt was made for Python with PyGUI but that seems to be making no progress. And, of course, there’s IUP www.tecgraf.puc-rio.br/iup/.
Another route is to create a platform-independent GUI library, either based on SDL2 or GLFW an OpenGL/Vulcan library for desktop GUIs. Or with one of the new minimalist libraries like libui (search github for libui) or nuklear (search github for nuklear).
Personally, so long as the same API applies to Linux and Windows, and it was Crystal’s official GUI library, I’d be glad to use any of these or with Qt or wxWidgets bindings).
PS reason for lack of links it that it only allows new users to put 2 links in a post!