I'd like to throw together a chess game, but I'd rather like to avoid writing actual chess AI. Are there any libraries out there that I can drop into an application without too much fuss? I've seen GNU chess but I'm led to understand that it's basically a console app that you could write a front end for. That's kind of clumsy, so I was hoping there was a smoother way to get a chess backend into my code.

Moved to AI.

I haven't searched for any Chess AI libraries, but my guess is that they don't exist. Chess is a specific application of more general AI techniques which heavily relies on heuristics which are unique to chess itself. In fact, the vast majority of the code for any chess program is the chess AI! You could probably find some general AI libraries for instance that would search a certain state space, but even then you'd have to come up with the chess heuristics and it would likely be more complicated than you desire.

Hence, I have a strong feeling that you'll have to use the GNU chess backend if you want a quality chess engine. After all, why would someone write a library if it could only be used for a very specific instance -- a chess program? Why not just write a chess program instead?