#!/usr/bin/perl

my $child=fork(); # Spawn off a child
if ($child>0) {
    #parent
    exec ($app1) || die "Could not exec $app1:$!";
    exit(0); # Should never get here!
} elsif ($child == 0 ) {
   # Child process
    exec ($app2) || die "Could not exec $app2:$!";
    exit(0); # should never get here either
} else {
     die "Could not fork! $!";
}

# Evaluating $! will give you the reason you couldn't 
# spawn the exec'ed process.