After writing Spiro Japh, I wished I had thought to use color.  But when ikegami very kindly pointed out to me the existence of the excellent Win32::Console::ANSI module, I created Spiro Japh 2, which works colorfully in both Linux and Windows ...

(You will need to install the Win32::Console::ANSI module to run it under Windows)

#!/usr/bin/perl                            -w -w -w -w -w
eval{     require                        Win32::Console::ANSI;
};sub      ::{printf                  @_ } sub            sub{
rand          39/999}               sub O123                 {::
""            ."\e[%d"            .";%dH%s"                  ,@_
;};               sub l234      {O123 $|=                    1
,1,                 "\e[J"}   while(1)                      {
$c                    or do {::"\e[1"                    ."".
 ""                    .";%dm", 30+                     rand
  7 ;                  l234;$u=&sub                  ;$v =
   &sub                ;$ c= 3999                 ;$b=qw
    /19 9            1/[int rand 3             ]};O123
     11*sin(      $v* $c)+    13,39*cos   ($u*$c)+41,
       qw+J A P H+[$c%4]        ;($a++%$b)or$c--;}
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Edit by demerphq: restored code tags
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