The simplest way is to use the barely documented system-with-a-first-argument-of-1 asynchronous system. It's not portable outside of Win32, but it is roughy analogous to appending '&' to the end of a unix command.

#! perl -slw
use strict;

if( @ARGV ) {
    print 'I am the child. I got args: ', join', ', @ARGV;
    sleep 10;
    print 'Child ended';
}
else {
    print 'I am the parent';
    for ( 1 .. 3 ) {
        print "Starting child $_";
        system 1, $0, 'An arg', $_;
    }
    print 'Parent continuing';
    sleep 10;
    print 'parent exiting';
}
__END__
c:\test>junk
I am the parent
Starting child 1
Starting child 2
Starting child 3
Parent continuing
I am the child. I got args: An arg, 2
I am the child. I got args: An arg, 3
I am the child. I got args: An arg, 1
parent exiting

c:\test>Child ended
Child ended
Child ended
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