For my cs512 class (Advanced Data Mining), I'm re-implementing CloSpan and CISpan, and am going to add to them FloSpan (or whatever I call it). In order to do this, I've built up some common libraries and I'm calling the overall framework 'Caravan'. I've actually started from scratch twice already!
See Introduction to Frequent Sequential Pattern Mining for some background information on what this is all about, and what it is good for.
Since this is an assignment, I'm going to be writing a paper. Someday I'll link to it.
As usual, my code is in darcs, grab it with:
# Original, modular version darcs get http://thelackthereof.org/projects/ocaml/caravan
# New fancy object-oriented version darcs get http://thelackthereof.org/projects/ocaml/caravan2
or from my github mirror. See Contributing for general hacking info.
I should put together an example usage :)