The libffi library provides a portable, high level programming interface
to various calling conventions. This allows a programmer to call any
function specified by a call interface description at run-time.

FFI stands for Foreign Function Interface. A foreign function interface
is the popular name for the interface that allows code written in one
language to call code written in another language.
The libffi library really only provides the lowest, machine dependent
layer of a fully featured foreign function interface.
A layer must exist above libffi that handles type conversions for values
passed between the two languages.
