column view of hierarchical text

[Douglas Ivers]

I want to display a hierarchy (think: outline) in the way that the  
Mac Finder does with column view.  Note that I am NOT interested in  
displaying files and folders, rather outline text.  I also want to be  
able to edit the text in the same view.

Example:

Fruit
Vegetables
Meat
Dairy
Grains

When I click on one of these, a new column appears to the right that  
shows the children, and the parent topic is highlighted in the first  
column.

Has anyone done this already in a Rev stack?

As an alternative, I'd be interested in a view that uses triangles to  
collapse and expand children, but I don't want to have to scroll up  
to the parent in order to collapse the list of children.

-Douglas Ivers