n-ary tree widget

[student]

Hi,  I have an application where i have a tree like structure that i
would like to be able to interact with.  Is there a tree widget with
collapsable/expandable branches.  For my particular application nodes
can have references to other nodes in the tree... for example

                               *
                              /|
                             / |
                            /  |
                         -------------
                         | / |   |   |
                         |/  |   |   | 
                         *   *   *   *

notice the first node in the 2nd row points to the root.  any node in
the tree should be able to point to any number of nodes.  Also I need
to bind keyboard events to each node in the tree and text based
information on each node.

I could write one myself, but I'm hoping i don't have too :) .. notice
also taht i'm not looking for a file structure type tree widget.  I
need to display it in a method similar to the tree above and it should
be able to expand / collapse the nodes interactively