I don't know the format of the data either, but it looks like there are three kinds of player: Java, Flash and plain-HTML. At least that'S what the Quia requirements page implies:
The quizzes seem to reside on the Quia site. Here's an example:
Jessica, is it possible to "download" or "backup" the Quia quizzes onto your own PC? If you could attach an example, we could give you more idea of what might or might not be possible.