I'm looking for a book detailing techniques for developing realtime multiplayer non-massive games, preferably focusing on the theory, rather than on APIs and underlying technology (sockets, DirectPlay, etc). Topics it would ideally cover are lag compensation, keeping stuff in sync, etc.
Does anyone know of any good book that matches the description?
Massively Multiplayer Game Development 1 and 2 had interesting coverage of the topics with references to other resources. Unfortunately, most published books are tied pretty closely to APIs, as you mention, in my experience.
Gamasutra articles, collectively, seem to be the best single resource on these topics (though unfortunately not in book form).
The Game Programming Gems series has a bunch of chapters on the subject strewn throughout. You could also look at old GDC talks or back issues of Game Developer.
Even though there's no good single book, there's a variety of papers. Yahn Bernier described Valve's technique in this article from 2000, and if you play grad student and look at the papers that cite that paper you can find other publications on the same subject.
Really multiplayer game programming is just a special application of the wider theory of distributed systems development, for which there's a lot of books. I learned from Mullender's textbook back in school but it was quaint then and badly out of date by now.