I really enjoyed this book! It is an alternate-Earth story, about what could happen if the plague wiped out most or all of Christianity.
Here is a review from Amazon.com: L. Neil Smith is most noted for his libertarian works. This novel is a bit different. It may be a study or lesson in libertarianism but if so I missed the lesson. That is not to say the novel is boring or not worth the read. Far from it. This is an alternate history novel and one done very well.
In L. Neil Smiths future the Europeans and Christians or gone due to a plague which was far more demonstrous then the one encountered in our timeline. This is a very similar premise to what Kim Stanley Robinson used 15 years later in his "Years of Rice and Salt". Smith does it better. In this novel the event change had a clear plot purpose where as in Robinson's novel I never quite got the point.
A densely written novel which requires careful reading and can not be skimmed through. If you give the novel the effort is deserving of you will enjoy the encounter. A worthy novel which should come back into print.