Since Scheme foreign function interfaces tend to be thin on
documentation, I started collecting examples here:
<https://github.com/schemedoc/ffi-cookbook>. Feel free to add new
examples, and new implementations of existing ones.

We could perhaps merge these into the Schematics Scheme Cookbook that we
inherited once we can figure out its copyright situation. However, FFI
examples are more complex than the usual cookbook code snippets since
it's really helpful to include build scripts and other auxiliary files.
Those are not essential for simple code that's all in Scheme.