I just recently found an interesting site that combines library listings from across the world. While it's not a comprehensive list of every single library, WorldCat promotes itself as having "Over 1 billion items in more than 10,000 libraries worldwide.
That's a lot of books!
I noticed that "The Developers" is listed in just seven libraries, although they do pretty much span the United States. Since the book is still relatively new, I'm sure this number will continue to grow, and I look forward to tracking it on WorldCat.