hmmm... that doesn't seem to work properly for me. For starters the line:

my $sz = $ARGV[1] || 8;
[download]

looks suspicious, I think it should be $ARGV[0]. But even after changing that, I'm not getting any output from the above program.

% ./queens 10
% ./queens 2
Board must be >= 4x4
[download]

-Blake