Joe, > Regarding efficiency, can someone comment on whether there is any difference > between the stream and continuation models in the effect on parallelism? Parallelism could be ENHANCED by a suitable continuation I/O model, such as the one I am working on (slowly), since with asynchronous I/O, you can carry on with calculations after submitting an I/O request (unless you are explicitly waiting on the result of an I/O operation), and I/O requests themselves may sometimes be safely carried out in parallel. _______________________________________________________________________________ [EMAIL PROTECTED] Evan Ireland, Department of Computer Science, +64-6-3569099 x8541 Massey University, Palmerston North, New Zealand.