This chapter describes SBCL's interface to C programs and libraries (and, since C interfaces are a sort of lingua franca of the Unix world, to other programs and libraries in general.)
Note: In the modern Lisp world, the usual term for this functionality
is Foreign Function Interface, or FFI, where despite the
mention of “function” in this term, FFI also
refers to direct manipulation of C data structures as well as
functions. The traditional CMUCL terminology is Alien Interface, and
while that older terminology is no longer used much in the system
documentation, it still reflected in names in the implementation,
notably in the name of the SB-ALIEN
package.