[Jach]

If you're interested in FFI, then yeah CFFI is the standard. The other comments addressed speed, I also wanted to point out https://github.com/rpav/cl-autowrap which is built on top of CFFI and can help get a wrapper up and running faster. After using autowrap's c-include you can then use CFFI basically like normal or some useful autowrap/plus-c's helper functions -- e.g. in one project, I have an SDL_Event (https://wiki.libsdl.org/SDL_Event) and to access event.key.keysym.scancode I have a helper function that's just (plus-c:c-ref event sdl2-ffi:sdl-event :key :keysym :scancode). Last year I wanted to try out using FMOD, and even though it's closed source and has a (to me) "interesting" API things worked easily: https://gist.github.com/Jach/dc2ec7b9402d0ec5836a935384cacdc... More work would be needed to make a nice wrapper, type things more fully, etc. but depending on the C library you might find someone's already done that (or made a start) and made it available from quicklisp.