"Stuart 'Zen' Bishop" wrote Point in time rollback Possible to add hooks to allow viewing of previous revisions of documents into Zope, perfect for Document Management products. Not only undo, but in theory it would be possible to support branching and merging if Zope became intelligent enough (loosly distributed databases anyone?)
A thought I've had is that you could get a 'point in time' view with the current FileStorage by simply stopping reading after X bytes - since the file is just appended to, this will show the ZODB as it was at that state.
From the UML models, tho, the FileStorage doesn't write down a timestamp with each transaction - ah, but Mr SourceCode says that the transaction ID is a timestamp. Exceeellent.
Sure, you'd want to make it a readonly view, but it could still allow some recovery for when someone's made a godawful screwup. Anthony