This script is a close variant of Re^2: [ASCII art graphs] Kisses. It's drawing Lissajous curves in ascii-art.

Big thanks to dewey and blazar who gave me the idea in that thread.

`#!perl
use warnings; use strict;
sub pie() {
2 * atan2(1, 0);
}
sub asin {
atan2($_[0], sqrt(1 - $_[0]**2));
}
sub liss {
my($p_m, $p_n, $p_d) = @_;
my($ht, $wd) = (24, 60);
my $ou;
for my $l (0 .. 2 * $ht - 1) {
0 == $l % 2 and $ou = " " x ($wd + 1);
my($y0, $y1) = (2 * $l / (2 * $ht) - 1, 2 * ($l + 1) / (2 * $h
+t) - 1);
my($su0, $su1) = (asin($y0), asin($y1));
for my $br (0 .. $p_m - 1) {
for my $sgn (0, 1) {
my($u0, $u1) =
($br * 2 * pie + $sgn * pie + $su0 * ($sgn?-1:1),
+$br * 2 * pie + $sgn * pie + $su1 * ($sgn?-1:1));
my($v0, $v1) = ($u0 / $p_m * $p_n + $p_d, $u1 / $p_m *
+ $p_n + $p_d);
my($x0, $x1) = (sin($v0), sin($v1));
$x1 < $x0 and ($x0, $x1) = ($x1, $x0);
int(($v0 - pie / 2) / 2 / pie) == int(($v1 - pie / 2)
+/ 2 / pie) or
$x1 = 1;
int(($v0 + pie / 2) / 2 / pie) == int(($v1 + pie / 2)
+/ 2 / pie) or
$x1 = -1;
my($p0, $p1) = (($x0 + 1) / 2 * $wd, ($x1 + 1) / 2 * $
+wd);
my ($ps, $pd) =
int($p0) < int($p1) ?
(int($p0), int($p1) - int($p0)) :
(int(($p0 + $p1 + 1) / 2), 1);
my $repl = \substr($ou, $p0, $pd);
0 == $l % 2 ?
$$repl =~ y/ /'/ :
$$repl =~ y/ '/,;/;
}
}
1 == $l % 2 and print $ou, "\n";
}
}
for (0 .. 19) {
print "\n" x 4;
my $r = sub { int(1 - log(1-rand(0.999)) / $_[0]) };
my($m, $n) = (&$r(0.7), &$r(0.9));
liss $m, $n, rand(2*pie);
sleep 3;
}
__END__
`

Here's an example output:

` ,'''', ,'''''', ,'',
; ', ,' ', ,' ',
; ; ; ; ; ;
; ; ; ', ; ;
; ; ; ', ,' ;
; ', ; ', ; ;
; ',; ', ; ;
; ;' ; ,' ;
; ,'; ; ; ;
; ; ; ; ; ;
; ; ', ; ,' ;
; ,' ', ', ; ;
; ; ; ; ; ;
; ; ; ; ,' ;
; ,' ', ; ; ;
; ; ', ',; ;
; ; ', ;, ,'
; ,' ; ,'; ;
; ; ; ,' ; ;
; ; ; ,' ; ,'
; ,' ; ,' ', ;
; ; ', ,' ', ,'
; ; ', ,' ', ;
;,' ',,,,,,' ;,,,'
`

**Update:** liverpole pointed out to Spiro Japh, his obfu that's also producing Lissajous curves.