entropia

Just because javascript drag-and-drop libraries are so abundant, that doesn’t mean there’s no benefit to writing your own.  Small tools like that can be written in a few hours and written well in a couple days.  And doing so will help you learn techniques you might not have tried before and give you experience.  Plus, in the end you’ll have exactly what you want.  No bloat from libraries that try to do everything.  No bugs or “features” that you can’t fix or don’t understand.

Here is my new, simple, drag-and-drop.  What separates it from others, I think, is that mine uses Towers of Hanoi as an example of customizing the drag/drop rules.