Dawn of Worlds is an open source rules system that takes the daunting task of world creation and turns it into a mini-game that encourages the players themselves to create their own world.
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
you will have instant access to your previous versions. Plus, you get a 15-day free trial, so there's nothing to lose.