This is a heuristic search framework that I wrote once upon a time,
back when I was into OCaml. Its tiny and I never really did anything
with it, but I think that it's kind of nice. However, it's a bit
obtuse if you aren't into OCaml's functors.

I haven't tried building it in years. In fact, it relies on a custom
build system called ocm2 that you probably don't have access to (email
me if you are extremely interested and perhaps I'll put it up here
too). You can probably write a Makefile for it easily.