Heroes of Oz is a Fudge roleplaying game by Mike Conway. Founded firmly in the Oz books by L. Frank Baum, in Heroes of Oz the Fudge system has been adapted to not only let you play in Baum's wonderful land, but also any other version of Oz you can imagine.
You are not limited to one version of Oz that's carved in stone by the game designers, and you don't have to houserule the game to play the Oz you want. Out of the box (well, book actually), Heroes of Oz can handle anything you throw at it. So play that space alien or that cyborg. Write up the hobbit that lives in the backwoods of the Gillikin country. While neither aliens, cyborgs nor hobbits are covered in the core rules, you can still play them easily with no changes to the rules. Do it.
For more information about Heroes of Oz, see "Heroes of Oz RPG: The Most Authentic Oz Roleplaying Experience" Facebook page.
Mike has provided two Heroes of Oz .pdfs you can download from the Fudge Files repository: