treeview

A tree view widget presents hierarchical data such that it can be navigated by expanding and contracting nodes of the tree.

The canonical tree view distributed with Tk since 8.5 is ttk::treeview

Alternative Tk Tree View Widgets

tablelist

a multi-column listbox and tree widget that has received a good deal of positive review

TkTreeCtrl

BWidget::Tree

ttk::treeview

bundled with Tk since 8.5. Intended to provide something that's a little more powerful (and faster) than the BWidget::Tree widget, and a little bit simpler to use (though less powerful) than the TkTreeCtrl widget.

Tix

Other Tree View Widgets

gnocl::tree