PHP Based API creates a tree structure using a couple of
small PHP classes. This can then be converted to javascript
using the printMenu() method. The tree is dynamic in
IE 4 or higher, NN6/Mozilla and Opera 7, and maintains state
(the collapsed/expanded status of the branches) by using cookies.
Other browsers display the tree fully expanded. Each node can
have an optional link and icon. New API in 1.1 with many changes
(see CVS for changelog) and new features, of which most came
from Chip Chapin (http://www.chipchapin.com).

WWW: http://pear.php.net/package/HTML_TreeMenu/