Most fantasy worlds manage to sustain a roughly medieval level of development for thousands of years at a stretch. (I blame hyperconservative nigh-immortal elves for quietly holding back technological progress.) Walter Jon Williams’ Metropolitan takes that restriction off and follows it to its logical conclusion, with geomantic public works and the essence of magic on tap as a utility; it’s a great read for gamers and anyone who likes to play with the idea of technomagic. The author discusses the worldbuilding and where to find the ebook.
I’m hoping there will be enough interest in this (and the sequel, City On Fire, when it comes out soon) that we can talk WJW into holding a Kickstarter for writing the third book that answers some of the questions raised in City On Fire.