http://privateerpress.com/company/iron-kingdom-rpg-source-books-now-available-in-pdf
http://rpg.drivethrustuff.com/index.php?manufacturers_id=121
Even though they have their own system in the works (probably in the pre-alpha stage),
these books are available through pdf. I know nothing about the type of DRM being used
on the books, nor do I know anything about their quality. They average 30 bucks, so it's
not something to purchase lightly.
If you're wondering what the big deal is, it's that the books are no longer in print since
their runs were something of a niche market within a niche market. People paid high prices
to get their hands on the books via Ebay. I'm glad now that they have some kind of
viable method to get this material.