MS XML Notepad 2007 <BR><BR>edit: just to clarify, this is an xml file editor that has a tree view pane on the left. You can right click and expand the whole tree, or leave it collapsed.

A meta-language for simplifying the process of making sentence diagram trees in Graphviz - dmsnell/graphviz-tree-graphs ...

Data viz isn’t just a modern-day craze. Designer Manuel Lima, author of The Book of Trees, discusses the origins of the tree diagram.