Write a "palipolyquine": a program that is a quine, a polyglot, and a palindrome.


  • The number of polyglot languages is more preferable than code size.
  • The shortest answer (in bytes) wins, in case of a tie.
  • Polyglot and Quine rules see here: Write a Polyquine.

My example (I have a repository Freaky-Sources with tests):

C#/Java (1747 bytes):

using System;//\u002A\u002F
class Program{public static void//\u000A\u002F\u002A
(String[]z){String s="`**?`@#_^using System;?_#^class Program{public static void?@#_^Main?_#main^(String[]z){String s=!$!,t=s;int i;int[]a=new int[]{33,94,38,64,35,95,96,63,36};String[]b=new String[]{!&!!,!&n!,!&&!,!&@!,!&#!,!&_!,!`!,!?!,s};for(i=0;i<9;i++)t=t.?@#_^Replace?_#replace^(!!+(char)a[i],b[i]);t+='*';for(i=872;i>=0;i--)t=t+t?@#_^[i];Console.Write?_#.charAt(i);System.out.printf^(t);}}/",t=s;int i;int[]a=new int[]{33,94,38,64,35,95,96,63,36};String[]b=new String[]{"\"","\n","\\","\\u000A","\\u002F","\\u002A","/","//",s};for(i=0;i<9;i++)t=t.//\u000A\u002F\u002A
A200u\F200u\A000u\//.t=t)++i;9<i;0=i(rof;}s,"//","/","A200u\\","F200u\\","A000u\\","\\","n\",""\"{][gnirtS wen=b][gnirtS;}63,36,69,59,53,46,83,49,33{][tni wen=a][tni;i tni;s=t,"/}};)t(^ftnirp.tuo.metsyS;)i(tArahc.#_?etirW.elosnoC;]i[^_#@?t+t=t)--i;0=>i;278=i(rof;'*'=+t;)]i[b,]i[a)rahc(+!!(^ecalper#_?ecalpeR^_#@?.t=t)++i;9<i;0=i(rof;}s,!?!,!`!,!_&!,!#&!,!@&!,!&&!,!n&!,!!&!{][gnirtS wen=b][gnirtS;}63,36,69,59,53,46,83,49,33{][tni wen=a][tni;i tni;s=t,!$!=s gnirtS{)z][gnirtS(^niam#_?niaM^_#@?diov citats cilbup{margorP ssalc^#_?;metsyS gnisu^_#@`?**`"=s gnirtS{)z][gnirtS(
A200u\F200u\A000u\//diov citats cilbup{margorP ssalc
F200u\A200u\//;metsyS gnisu

Compilation available on ideone.com: C#, Java.

  • 2
    \$\begingroup\$ Are there any rules involved in making the poly-quine? Any limitations? If this question is as-is, then a possible (trivial) solution is 1 (which will output 1 in many languages here, and is palindromic). \$\endgroup\$
    – clismique
    Sep 15, 2016 at 11:39
  • \$\begingroup\$ I added more formal rules. \$\endgroup\$ Sep 15, 2016 at 11:48
  • 2
    \$\begingroup\$ Ah, cool. Well, good luck on your first challenge! Just some more things though: you don't really need the code block there, and you should probably migrate the rules from the other challenge over to here. \$\endgroup\$
    – clismique
    Sep 15, 2016 at 11:52
  • 1
    \$\begingroup\$ Does a 5-language, 999-byte answer beat a 4-language, 100-byte answer? \$\endgroup\$ Sep 15, 2016 at 13:15
  • \$\begingroup\$ @ETHproductions, I think yes. It's harder to add new language than reduce number of lines. \$\endgroup\$ Sep 15, 2016 at 13:20

2 Answers 2


CJam/GolfScript, 2 languages, 50 bytes


Try it CJam! Try it in GolfScript!

Huh, this went unanswered surprisingly long.


It's probably easiest to explain this by showing how I turned the basic quine in each language into a palindromic polyglot quine.

So the basic quines in both languages are:



In GolfScript and CJam, respectively. These are quite similar thanks to the fact that CJam was originally inspired by GolfScript (but has since deviated quite a lot). The first difference we notice is that one uses . for duplicating the top of the stack and the other uses _. A common trick to avoid this problem is to use 0$, since both languages have the "copy-nth-item-on-stack" operator $. So we get {"0$~"}0$~, although that still needs a trailing linefeed in GolfScript. But let's worry about that at the end.

First, we need to make it a palindrome. The obvious solution to this is to append a comment and put the source code there in reverse. This is quite simple, because CJam uses e# for comments, and in GolfScript e does nothing at all, and # is a comment. So if we append e#... that works for both languages. Here is what we've got:


Of course, that doesn't actually print the part from e# onward. We can reconstruct this quite easily from the source code itself. Both languages can turn the initial block into a string with ` and append the "0$~" part with +, so that we get the entire unmirrored source code in a single string. To append a mirrored copy, all we need to do is duplicate the string with 0$ again and then reverse it with -1%, which also works in both languages. So now we've got this:


This is a valid palindromic quine in CJam, and it also works in GolfScript but still prints that pesky trailing linefeed.

The usual way to prevent this is to assign an empty string to n, because what GolfScript really does is print the contents of n at the end. So what we need is "":n. So what about CJam? Thankfully, this does nothing at all. "" is also an empty string (or empty list, they're the same thing in CJam), and : maps the operator n (print with linefeed) over the list. But since the list is empty, mapping an operator over it does nothing at all. Hence, we can get rid of the linefeed, without messing with CJam, and end up with the final solution:


Perl 5/Ruby/PHP/JavaScript (Browser), 4 languages, 513 bytes

$_='$z=0?"$&".next: eval("printf=console.log;atob`JCc`");printf("%s_=%s%s%s;eval(%s_);//#//;)_%s(lave;%s%s%s=_%s",$d=$z[0]||h^L,$q=$z[1]||h^O,$_,$q,$d,$d,$q,"0"?$_.split("").reverse().join(""):~~reverse,$q,$d)';eval($_);//#//;)_$(lave;')d$,q$,esrever~~:)""(nioj.)(esrever.)""(tilps._$?"0",q$,d$,d$,q$,_$,O^h||]1[z$=q$,L^h||]0[z$=d$,"s%_=s%s%s%;eval(s%_);//#//;)_s%(lave;s%s%s%=_s%"(ftnirp;)"`cCJ`bota;gol.elosnoc=ftnirp"(lave :txen."&$"?0=z$'=_$

Try the Perl online!
Try it online!
Try the PHP online!
Validate it online!

$_='$z=0?"$&".next: eval("printf=console.log;atob`JCc`");printf("%s_=%s%s%s;eval(%s_);//#//;)_%s(lave;%s%s%s=_%s",$d=$z[0]||h^L,$q=$z[1]||h^O,$_,$q,$d,$d,$q,"0"?$_.split("").reverse().join(""):~~reverse,$q,$d)';eval($_);//#//;)_$(lave;')d$,q$,esrever~~:)""(nioj.)(esrever.)""(tilps._$?"0",q$,d$,d$,q$,_$,O^h||]1[z$=q$,L^h||]0[z$=d$,"s%_=s%s%s%;eval(s%_);//#//;)_s%(lave;s%s%s%=_s%"(ftnirp;)"`cCJ`bota;gol.elosnoc=ftnirp"(lave :txen."&$"?0=z$'=_$


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