Self-reproducing code.

Here is such an entertaining code that got caught on the net.
The program draws a spinning spiral consisting of its own code.
Flexibility perl'a in action so to speak)

#! / usr / bin / perl
$ _ = '
         $ q = "\ 47"; wh
        ile ($; =
      $ z + = .5) {
    % c = $ r = 0; $ / = ""; whi le (2
   0+ $ z> ($; + =. 05)) {$ c {int $ _ + 2
  6+ 2 * ($ r + = .0 2) *
 s in $;} {1 - $ _
+1 0+ int $ r * cos
$;} = 1for (0. .1)} $
t = r ever se; $ /. = `
c le ar `. "#!
/ usr / bi n / pe
rl \ n \ $ _ = $ q \ n ";
fo r $ y (1..20) {$ c {$ _} {
$ y}? $ /.=chop$t:
 ($ /. = "\ 4
 0 ") for (0 .53);
   $ /. = "\ n"} pri nt "$ / $ q;
   s; ". chr (9 2)." s ;; g; eval \ n "}
'; s; \ s ;; g; eval

A source