This is wonderfully simple! Where yesterday I processed sequentially like this:

   ...
   foreach (@jobs) {
      &process($_);
   }
   ...
[download]

Today, in parallel with just a few changes ripped from 'afork':

   ...
   foreach (@jobs) {
      die "Fork failed: $!\n" unless defined (my $pid = fork);
      exit &process($_) unless $pid;
   }
   1 until -1 == wait;
   ...
[download]

And restrained parallel with three more lines:

   ...
   my $max = 4;
   my $c   = 0;
   foreach (@jobs) {
      wait unless ++$c <= $max;
      die "Fork failed: $!\n" unless defined (my $pid = fork);
      exit &process($_) unless $pid;
   }
   1 until -1 == wait;
   ...
[download]

I wonder where the once-prominent abigail is today...