> I've always wished for a _simplified_ Morphic written in Ruby.
>
> If it's implemented on top of an existing GUI toolkit, it's on average
> worthless. If you're thinking about building it on top of a canvas, well,
> most canvases are GUI toolkits in their own sense. Morphic combines the
> power of the canvas and the non-canvas widgets in one coherent system.

Based on your response and some of the others, it's becoming clearer that
there's a lot more to Morphic than I understood. What I was specifically
looking for was an established API, that people already enjoy programming
with, for creating shapes on a canvas and dragging them around, etc. to be
used as an add-on for FXRuby. From what you and some others have suggested,
Morphic is itself an entire GUI system (and more?) and not just this limited
subset I had in mind.

FOX already has a very nice system for creating shapes and then dragging
them around in 3-D -- namely, the OpenGL-based FXGLViewer and its associated
classes. But there's nothing similar for 2-D, so you couldn't easily
construct an application for, say, drawing diagrams with interconnected
shapes. Tk's Canvas widget does support these kinds of applications pretty
well, and I always thought FOX would benefit from something similar. So my
options are to either strike out on my own and come up with a new API, or to
instead look for an existing API with a similar purpose and start from that
instead.

I am still planning to look into the Morphic references that you, Alexander
and Horacio have provided. It now seems more likely that, if I do end up
liking Morphic in general, what will instead end up in FXRuby is a "Morphic
lite" of some kind.