Is there any Tree Control for RoR?
No, not really. You'll probably have to learn how to generate an
unordered list and skin it with css.
Look around for a Rails plug-in. I'm sure someone's created
Just Google around and you'll find something. I just did a search and
this one looked maybe promising (although I haven't used it myself):
We use the Yahoo YUI treeview control, and my colleague Christopher
Haupt wrote an article on how we implemented it in Rails: