[Tcllib] contains a tree data structure. Documentation for it can be found at http://tcllib.sourceforge.net/doc/tree.html . This module of the [tcllib] data [struct]ures collection provides the data structure portion of a tree structure. Also, [BWidget] has a [Tree] widget. (See [Tree nodes in motion] - [starDom] - [LemonTree]). ---- The tcllib Tree would be more useful if nodes could be arbitrary objects (specifically, if they could be [incr Tcl] objects.) To that end, I made some mods which [string map] {:: @} in the creation of [namespace] data arrays. Worth adding to the mainline? [CMCc] ---- For a lightweight approach, see [Trees as nested lists]. ---- Related topics: * [Containers] tree container command * [ODIE] environment which has tools for data tree maintenance * [RBTree] red-black tree data type * [Tree Objects] discussed by [Clif Flynt] * [Various useful Tcl packages (Rempel)] includes some tree operation packages * graphical representation of tree data * a "tree widget", often for filesystem data, which appears in particular the [TkTreeCtrl] widget, tree widgets from the [Hipp miscellaneous widgets], [mtree widget], as well as the [BWidget], [BLT], [Tix], [ClassyTk], [incr widgets]' hierarchy widget, [mkWidgets], [PRS Open Source Software], [Zinc] packages, and the pure-[Python] TreeWidget [http://oomadness.tuxfamily.org/p-treewidget.php] for [Tkinter]. * [Tk Tree Widget in C++], [tkgcv], [hierarchy], [Tree Table], born2net's iwidget version of Hipp's tree widget, Brighton's iwidget tree widget, Mutlu's iwidgets version of a tree widget, Pryce's itk widget base class are some older examples of tree widget implementations * Also check out [tktree] for a tcl/tk tree widget ---- [[ [Arts and Crafts of Tcl-Tk Programming] | [Category Command], package [tcllib], module [struct] | [Category Data Structure] | ]]