Ah, excellent, another oppurtunity to plug "Ventus", by Kurt Schroeder
This is an excellent piece of space-opera that takes the concepts of nanotechnology to the limit. An entire terraformed world wherein the inhabitants are at the mercy of nanobotic gods called the Winds, who violently block any efforts by the humans to advance beyond simplistic mechanisms. The Winds were originally the terraformers meant to do man's bidding, but something went wrong. Cue the arrival of several mysterious off-worlder government agents the very concept of which many of those on Ventus find difficult to cope with.
Has a few flaws, but Schroeder is one of those rare few authors who follow their ideas all the way to the end, like more logical versions of Doc Smith and Burroughs. The amount of imagination is impressive, the story tight, and the characters likeable. There is also a strong draw for anyone hankering for a decent female lead.
Sorry, I waffled.
EDIT: Um, this isn't particularly hard as sf goes, but quite hard nonetheless. Soft on a hard base, like cheesecake, if you will.