I think I asked roughly this question several years ago, but I would appreciate a reminder. In several read-eval-print loops for functional languages (e.g. Poly, SML/NJ, various LISPs), it's possible to save and restore the current state so you can start up again in an environment with all the same objects and name bindings present. OCaml does not currently allow this. How hard would it be to modify OCaml to support save/restore of sessions? At the moment I'm forced into OS-specific checkpointing of processes. John.