Besides, if you have data with interdependency data, AND you want to use multiple processors, or a 'grid', you will have serious problems to treat with the multiprocessing, whatever techinics you will to use.

So in this case, I recommend MPI libraries, because you have the possibility of send data between processes(and the control of this by the processors), and this was made in C language. Perl have some support to MPI, but I never used it(RTFM CPAN). So, if you have inderdependency to data, this is not a problem(but is complicated ;) ), with MPI.

Now, if you don't have a interdependency, you can just to use forks package(threads clone, but you don't need to activate thread mode), or some library that manipulates forks, or some other package. Check this in CPAN, RTFM and have fun!!