I was mildly curious and directly went for performance results.
A few bits of information for those that dont want to explore the website
themselves :

- it's a really big data set; on the website you're advised to
    export OCAMLRUNPARAM='h=5G;s=1G'

- the Haskell implementation was developped first, tuned, and now takes 17
minutes to run. The OCaml implementation is a simple port of the Haskell
implementation (with the data structures adapted), and it takes 15 minute to
run. A younger Clojure implementation is at 30 minutes for now.

My hasty conclusion : the OCaml GC and the Hasthbl implementation scale
well.