So far, as far as I can tell, there is no Ruby IDE with GUI
capabilities.

What I want to understand is: How can there be Gambas and yet Ruby
lacks a GUI interface?

I've been reading about Ruby and considering learning it and using it
exclusively but I'm not a command-line man and I don't want to have to
manually figure out all the GUI widgets and whatnot so I'm curious if
any one knows of any current project underway to make a new Ruby IDE
with GUI capabilities???