Check out jqTree for a more up to date plugin.
Lightweight and flexible transformation of an unordered list into an expandable and collapsable tree, great for unobtrusive navigation enhancements. Supports both location and cookie based persistence.
Provides some options for customizing, an async-tree extension and an experimental sortable extension.
.treeview( options )
Takes an unordered list and makes all branches collapsable. The "treeview" class is added if not already present. To hide branches on first display, mark their li elements with the class "closed". If the "collapsed" option is used, mark initially open branches with class "open".
Copyright Jörn Zaefferer
Released under the MIT license: