Thanks to Erik Tenkar for pointing this out.
There is a Humble Bundle of Warhammer Fantasy Role-Playing game books.
$1 will get you the WFRPG rulebook, 2nd edition, in PDF, plus three books.
Higher tiers will get you more.
II went in for it - $1 for something to read on my Kindle on vacation. WHFRPG 1st edition made my head spin, with all of the misery of being a spellcaster, profession-hoping, and mechanics I couldn't quite understand right away. But it had nice flavor (flavour?) to it. You can throw in more for more books, or just to support the charities they're supporting.