Perl module to limit the number of child processes

 Proc::Queue lets you parallelise a perl program using the fork, exit, wait
 and waitpid calls as usual but without taking care of creating too many
 processes and overloading the machine.
 .
 It redefines perl fork, exit, wait and waitpid core functions. Old programs
 do not need to be reprogrammed, only the use Proc::Queue ... sentence has to
 be added to them.