I thought people would enjoy this excerpt from a New York Times
"Our expectations that any action can be taken back have been primed
by a few decades of personal computing, which injected the founding
metaphor of undoing into the common consciousness. An early glimmer
of our Age of Undoing appeared in a prescient 1976 research report by
Lance A. Miller and John C.
I am currently working on the design of a blogging system (ala
WordPress, Movable Type) as an exercise of my independent study. As
part of the design, I would like to design and implement an
application-wide cascading undo model such as the one described by
Jan Vratislav (http://bit.ly/UYerR) In this model, undos are based on
a "cascade" of hierarchal actions in the history, whereby a user can
selectively undo an action (which also undos every subsequent action
in that action's hierarchy).