The World Born Dead
Unknown Armies
http://www.scc.net/~indra/ua/index.html
Ascendant campaigns can view previous versions of their pages, see what has changed (and who did it), and even restore old versions. It's like having a rewind button for your campaign.
We've already been saving your edits, so if you upgrade now you will have instant access to your previous versions. Plus, you get a 15-day free trial, so there's nothing to lose.