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 something.
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): http://linux.wareseeker.com/Internet/ajax-tree-control-0.1.zip/318020
Nicholas
We use the Yahoo YUI treeview control, and my colleague Christopher Haupt wrote an article on how we implemented it in Rails:
http://www.buildingwebapps.com/articles/12-using-yahoo-s-user-interface-library-treeview
Michael Slater www.BuildingWebApps.com