As luck would have it, I just posted v1.3 of Enumerable Tools on the RAA, which now has some tree stuff. It's at http://redshift.sourceforge.net/enum/ It may not be what you're looking for, but take a look at tree.html. It describes tree.rb, which has some methods for iterating depth-first or breadth-first over a collection of objects that have some tree structure (or directed acyclic graph structure). This isn't a Tree class, or an optimization like red-black trees or anything like that, just two ways of making a tree into an Enumerable thingy. It's fairly flexible in working with different ways of defining the children of a node. HTH "Phil Mitchell" <phil.$DELETEmitchell / pobox.com> wrote in message news:1103_1000692909 / dread... > Aside from Yoki Toshinori's binary tree lib, does anyone have native ruby code for trees? Specifically, I need rooted, > multiway trees, but I would appreciate any related material -- I'm just getting started with ruby. >