While myDVDEdit is still only at a beta 0.8 version, I thought we’d report this now in case someone needs it now. myDVDEdit lets you go back into the structure of the DVD and make changes. The goal of the developer of myDVDEdit, Jérôme Cabanis, is to create a tool that helps use all understand and modify the content of the DVD without going back to DVD Studio Pro. (It will certainly work with DVDs authored with another application as long as copy protection has not been applied.)
It lets you get into the structure of the DVD at the deepest level through a (relatively) simple Graphical User Interface. It’s on a very rapid development path and the author is very open to suggestions for what it needs to become a complete tool. (Another reason for adding it to the news now.)
There’s a good overview of the product, translated from the French of the author at Editor’s Bin. Frankly that page is such a good overview of the DVD Structure it’s going in the Hub Articles index. It should be required reading for anyone who wants to understand how a DVD is structured after it’s “built” by DVD Studio Pro.
myDVDEdit is currently (and probably will remain) freeware and similar in concept to TFDVDEDIT, although at a very much more basic and incomplete level.