Announcing node.ocaml (OCaml + Libevent = Fast Fun)

You might want to consider looking into using the LWT library? (http://ocsigen.org/lwt/)

It's fairly mature, has a bunch of standard libraries already wrapped up into continuation-passing / callback style (I believe this includes libev, a cousin to libevent) and has a nice syntax extension too that can save the typing required to explicitly wrap things into callbacks.

I still think that something like Arc + LLVM's vmkit + fast FFI and async IO is a still good idea. Anyone? ^_^