FM Synthesis Libraries

I'm thinking about using a realtime FM synth for music and sound effects in my next game. I'd write a library myself, but I don't want to waste my time if there's already something good out there. The thing is, google turned up no results. Am I going to have to get cracking on my own?

>>87
Use Jack on *nix if you can. If you're writing a synth, it's a fair bet you want to make music, so hooking into the usual system will be a plus.