This contest is officially over, the winner is jimmy23013. Congratulations!

The challenge is to make a program that prints Hello World! to stdout. The catch is that your program must have a Levenshtein distance of 7 or less from the program in the answer submitted before yours.

How This Will Work

Below I have already submitted the first answer using Python: print("Hello World!").

The next person to answer must modify the string print("Hello World!") with up to 7 single character insertions, deletions, or substitutions so that when it is run in any language that hasn't been used so far (only Python in this case) the output is still Hello World!.

For example the second answerer might use 1 substitution (r -> u), 2 deletions (in), and 1 insertion (s) to make the string puts("Hello World!") which prints Hello World! when run in Ruby.

The third person to answer must do the same thing in a new language, but using the program of the second person's answer (e.g. puts("Hello World!")) as their starting point. The fourth answer will be in relation to the third answer and so on.

This will continue on until everyone get stuck because there is no new language the last answer's program can be made to run in by only changing 7 characters. The communal goal is to see how long we can keep this up, so try not to make any obscure or unwarranted character edits (this is not a requirement however).


Please format your post like this:

# Answer N - [language]


[notes, explanation, observations, whatever]

Where N is the answer number (increases incrementally, N = 1, 2, 3,...).

You do not have to tell which exact characters were changed. Just make sure the Levenshtein distance is from 0 to 7.


The key thing to understand about this challenge is that only one person can answer at a time and each answer depends on the one before it.

There should never be two answers with the same N. If two people happen to simultaneously answer for some N, the one who answered later (even if it's a few seconds difference) should graciously delete their answer.


  • A user may only submit one answer per 8 hour period. i.e. Each of your answers must be at least 8 hours apart. (This is to prevent users from constantly watching the question and answering as much as possible.)
  • A user may not submit two answers in a row. (e.g. since I submitted answer 1 I can't do answer 2, but I could do 3.)
  • Each answer must be in a different programming language.
    • Different versions of the same language count as the same language.
    • Languages count as distinct if they are traditionally called by two different names. (There may be some ambiguities here but don't let that ruin the contest.)
  • You may only use tabs, newlines, and printable ASCII. (Newlines count as one character.)
  • The output should only be Hello World! and no other characters (a leading/trailing newline is not an issue).
  • If your language doesn't has stdout use whatever is commonly used for quickly outputting text (e.g. console.log or alert in JavaScript).

Please make sure your answer is valid. We don't want to realize there's a break in the chain five answers up. Invalid answers should be fixed quickly or deleted before there are additional answers.

Don't edit answers unless absolutely necessary.


Once things settle down, the user who submits the most (valid) answers wins. Ties go to the user with the most cumulative up-votes.

Leaderboard: (out of date)

(user must have at least 2 valid answers)

11 Answers

7 Answers

6 Answers

5 Answers

4 Answers

3 Answers

2 Answers

Languages used so far:

  1. Python
  2. CJam
  3. PHP
  4. Pyth
  5. Perl
  6. Befunge 98
  7. Bash
  8. Nimrod
  9. Ruby
  10. GNU dc
  11. Golfscript
  12. Mathematica
  13. R
  14. Lua
  15. Sage
  16. Julia
  17. Scilab
  18. JavaScript
  19. VHDL
  20. HyperTalk
  21. Haskell
  23. APL
  24. M30W
  25. Stata
  26. TI-BASIC (NSpire)
  27. ActionScript 2
  28. J
  29. PowerShell
  30. K
  31. Visual FoxPro
  32. VBA
  33. Extended BF Type III
  34. Zsh
  35. Dash
  36. Clojure
  37. NetLogo
  38. Groovy
  39. CoffeeScript
  40. Clipper
  41. B.A.S.I.C.
  42. FALSE
  43. fish (shell)
  44. GNU Octave
  45. TCL
  46. E
  47. newLisp
  48. Lisp
  49. SMT-LIBv2
  50. Racket
  51. Batsh
  52. tcsh
  53. AppleScript
  54. Mouse
  55. Pixie
  56. F#
  57. Falcon
  58. Burlesque
  59. HTML
  60. SGML
  61. M4
  62. MUMPS
  63. TeX
  64. Forth
  65. Salmon
  66. Turing
  67. bc
  68. Betterave
  69. Scheme
  70. Emacs Lisp
  71. Logo
  72. AutoLISP
  73. ///
  74. Rebol
  75. Maple
  76. FreeBASIC
  77. Vimscript
  78. ksh
  79. Hack
  80. mIRC
  81. Batch
  82. Make
  83. Markdown
  84. sh
  85. GDB
  86. csh
  87. HQ9+-
  88. Postscript
  89. Matlab
  90. Oz
  92. VBScript
  93. QBasic
  94. Processing
  95. C
  96. Rust 0.13
  97. Dart
  98. Kaffeine
  99. Algoid
  100. AMPL
  101. Alore
  102. Forobj
  103. T-SQL
  104. LiveCode
  105. Euphoria
  106. SpeakEasy
  107. MediaWiki
  108. SmallBASIC
  109. REXX
  110. SQLite
  111. TPP
  112. Geom++
  113. SQL (postgres)
  114. itflabtijtslwi
  115. RegXy
  116. Opal.rb
  117. Squirrel
  118. Pawn
  119. Scala
  120. Rebmu
  121. Boo
  122. PARI/GP
  123. Red
  124. Swift
  125. BeanShell
  126. Vala
  127. Pike
  128. Suneido
  129. AWK
  130. Neko
  131. AngelScript
  132. gosu
  133. V
  134. ALAGUF
  135. BogusForth
  136. Flaming Thunder
  137. Caché ObjectScript
  138. owl
  139. Cardinal
  140. Parser
  141. Grin
  142. Kitten
  143. TwoDucks
  144. Asymptote
  145. CAT
  146. IDL
  147. Tiny
  149. Io
  150. MuPAD
  151. Java
  152. Onyx
  153. JBoss
  154. S+
  155. Hexish
  156. yash
  157. Improbable
  158. wake
  159. brat
  160. busybox built-in shell
  161. gammaplex
  162. KTurtle
  163. AGOL 68
  164. Alice
  165. SML/NJ
  166. OCaml
  167. CDuce
  168. Underload
  169. Simplex v.0.6
  170. Minkolang 0.9
  171. Fexl 7.0.3
  172. Jolf
  173. Vitsy
  174. Y
  175. Retina
  176. Codename Dragon
  177. Seriously
  178. Reng v.3.3
  179. Fuzzy Octo Guacamole
  180. 05AB1E

(Feel free to edit these lists if they are incorrect or out of date.)

This question works best when you sort by oldest.

NOTE: This is a trial question for a new challenge type I have in mind where each answer depends on the last and increases in difficulty. Come discuss it with us in the chatroom for this question or in meta.

  • 61
    \$\begingroup\$ "Sort by oldest" is useful here. \$\endgroup\$
    – xnor
    Oct 27, 2014 at 6:39
  • 8
    \$\begingroup\$ chatroom for discussion on this question \$\endgroup\$
    – Justin
    Oct 27, 2014 at 7:04
  • 5
    \$\begingroup\$ @Mew HQ9+ prints the wrong message. But this one... esolangs.org/wiki/Huby \$\endgroup\$
    – Sp3000
    Oct 27, 2014 at 13:55
  • 17
    \$\begingroup\$ Maybe this can be interesting : migl.io/projects/hw. This list automatically the answers and display their life time. \$\endgroup\$
    – Michael M.
    Oct 27, 2014 at 15:00
  • 6
    \$\begingroup\$ @gerrit Cause I could really use 350 more answer notifications... \$\endgroup\$ Nov 4, 2014 at 1:39

184 Answers 184

3 4
6 7

Answer 135 - BogusForth

"/#class jux{//-ta[][static void main(){//println(;\#//Hello*}}

print""Hello World!"i"#!puts

Distance 7 from answer 134. (5 necessary, 2 for ic in static)


Answer 147 - Tiny

#class jux{//-ta][static void main(String[]){System.out.println(;\#//Hello*}}print,
"Hello World!"#;write"putsx;//-##[;]#bye</>%"

Distance 7 from answer 146

  1. remove ;
  2. remove /
  3. remove /
  4. removed \n (newline) to have print on above line
  5. added # after "Hello World" to comment out the rest of the trash.
  6. u int out
  7. t in out (hoping to see that java answer)

At this point I'm just looking through EVERY language in esolangs.org... haha


Answer 149 - Io

#class jux{public static void main(String[]){System.out.println(;\#//Hello*}}print,
"Hello World!"print"putsx;//-##[;]#bye</>%"

Distance 7 from answer 148 (6 necessary, 1 for the space after public).

Io supports both write("...") and "..."print, but not print("...") or "..."write unfortunately.

This question has most answers in this site now.


Answer 156 - yash

#B00class jux{public static void main(String[] h){
cat<<<"Hello World!" #;}}//print#putsx;//-##[;]#bye</>%"

Distance 7 from answer 155 (5 necessary, 2 change the single quotes to double quotes, to make next answers easier).

I'll stop looking for new languages now. And I'll be no longer answering so fast. I'll only post answers with languages that I have found but yet didn't have chance to use.

I also found apt-cache search useful. And if you want more languages that only a few people use, you can try something like this. If you want it to be uninteresting, you can also see here.

There are also many esolangs and serious languages in those long lists not have been used yet, I think.


Answer 153 - JBoss

//#class jux{public static void main(String[] h){
'Hello World!');//}}//print#putsx;//-##[;]#bye</>%"

Distance 7 from answer 152.

Note due to incorrect syntax the last line was changed... 2014-11-18 (OP)

  • \$\begingroup\$ ... Anyone has ideas fixing answer 154? \$\endgroup\$
    – jimmy23013
    Nov 20, 2014 at 2:57
  • \$\begingroup\$ About that.. :3 \$\endgroup\$
    – Timtech
    Nov 20, 2014 at 19:24

Answer 170 - Minkolang 0.9

Distance 7 from answer 169.

03w!(*#class jux{public static void main(String[] h){#
"Hello World!"(O).g!)S(#X` ;}}//printputsx;//-##E;]bye</>%#*)

The two additions are 03w at the beginning, which jumps it to the beginning of the fourth line and (O). after "Hello World!", which prints out the whole stack as characters. Very, very, very conveniently, this is exactly 7 characters!

  • 2
    \$\begingroup\$ Rise of the new golfing langs! \$\endgroup\$ Oct 26, 2015 at 22:54

Answer 172 - Jolf

Distance 7 from answer 171.

"#03w(*#class jux!{public static void main(String[] h){#\
a"Hello World!'#(O).g!)S(#X` ;}}//printputsx;//-##E;]bye</>#*)


  • Five insertions; "s at beginning and after put; \ after first two lines; a before "Hello World!
  • 1 substitution; ' to " on the last line
  • 1 deletion; the % towards the end.

Try it here!

  • \$\begingroup\$ Are languages newer than the challenge allowed? \$\endgroup\$
    – mbomb007
    Feb 24, 2016 at 21:37
  • \$\begingroup\$ @mbomb007 Yes, they are. \$\endgroup\$ Feb 24, 2016 at 21:49

Answer 174 - Y

Distance 7 from answer 173. Try it here!

"4mrZ""#03w(*#class jux!{public static void main(String[] h){#\

"Hello World!"gx;#(O).g!)S(#X` ;}}//printputs;//-##E;]bye</>#*)

Surrounded 4mrZ with quotes (2); added two characters gx after "Hello, World!". Added a newline after put", replaced the a with a ^, removed the x from printsputsx;// on the last line. Both 4mrZ and the long text after it are quoted and pushed to the stack; ^ probably does something, but nothing relevant, "Hello World!" pushes that sting to the stack, and g prints one item from the stack. x terminates the program. Fun fact: removing the x gives infinite "Hello World!"s because of the X, which wraps around to the beginning of the section.

  • \$\begingroup\$ @mbomb007 my pleasure! \$\endgroup\$ Feb 24, 2016 at 22:24

Answer 175 - Retina

x`4mrZ"#03w(*#class jux!{public static void main(String[] h){#\

Hello World!
gx`#(O).g!)S(#X` ;}}//printputs;//-##E;]bye</>#*)

Distance 7 from Answer 174.

The last line is simply an empty line, so the next person should remove <empty>. I used free-spacing mode so that # starts a comment. This takes care of the unmatched brackets and parentheses. I guess the g is the last replace's configuration string is ignored?

Try it online


Answer 177 - Seriously

H.`4mrZ"#03w(*#class jux!{public static void main(String[] h){#\

disp"Hello World!")
gx`#(O)X.g!)S(#X` ;}}//printputs;//-##E;]bye</>#*)`kX

The last line is intended to be empty; SE doesn't like blank lines at the end of code blocks.

Distance 6 from Answer 176


+ H. (at the start, prints "Hello, World!")
+ X  (before the first . on the last line; prevents extraneous printing by clearing the stack)
+ `kx  (at the end, finishes a function definition and clears the stack to prevent printing)
  • \$\begingroup\$ @mbomb007 This solution is intended to also have the empty line; SE apparently doesn't like blank lines in code blocks (which I didn't realize). \$\endgroup\$
    – user45941
    Mar 8, 2016 at 21:08
  • \$\begingroup\$ ^ yeah. It's annoying. It allows them if you use <code><pre> or something like it, but then it removes any < or >, which sucks for copy-paste purposes... \$\endgroup\$
    – mbomb007
    Mar 8, 2016 at 21:54

Answer 180, 05AB1E

i#^.`4mrZ"#03w(*#class jux!{public static void main(String[]ih){#\

is~ob]"Hello World!"q@)
gx`#(O)X.g!)S(#X` ;}}//printputs;//-##E;]bye</>#*)`kX

Distance 4 from Answer 179. Try it online!


The program starts with an if statement. Since the stack is empty, that makes all of i#^.`4mrZ"#03w(*#class jux!{public static void main(String[ no-ops. When it gets to ], it closes all if statements, loops, etc. But, right ahead of that is another if. Once again the stack is still empty, so all of


is a huge no-op. Next, p checks if top of stack is prime. Yet again the stack is empty, so it's also a no-op. Same goes with r; it just reverses the (empty) stack. Then the program encounters i with an empty stack again, so



is yet another no-op. Again, the ] exits all if statements, loops, etc. Next 05AB1E parses "Hello World!" as a literal string and pushes it to the stack. Finally, q exits the program, making the rest of the code a no-op, and implicitly outputs top of stack.


Answer 182 - Vyxal

kh\!#^.`4mrZ#03w(*#class jux!{public static void main(String[]ih){#\

is~ob]"Hello World!"q@)
gx`#(O)X.g!)S(#X` ;}}//printputs;//-##E;]bye</>#*)`kX

Try it Online!

Distance of 4 from the last answer.

Due to a parsing bug in the current version of Vyxal, everything after the kh\! is commented out, including the last two lines.


Answer 46 - E

println("Hello World!")#\

Distance 7.

I haven't actually run this. It may be that # comments must only have whitespace in front of them, in which case this is invalid, but I really doubt that.

  • \$\begingroup\$ I wonder if we could work backwards with unused languages and make the first two lines useable again. The second doesn't seem too hard, the first one is a different story though. \$\endgroup\$
    – Etheryte
    Oct 27, 2014 at 21:58

Answer 52 - tcsh

#//echo o[.>]tac;cat<<;#&&alert
(printf "Hello World!");

Distance 7 from answer 51.

  • 1
    \$\begingroup\$ Missing name for redirect. Too many )'s. \$\endgroup\$
    – jimmy23013
    Oct 27, 2014 at 23:42
  • 1
    \$\begingroup\$ It doesn't work. The first line gives Missing name for redirect. The second gives Too many )'s. It never prints Hello World! \$\endgroup\$ Oct 27, 2014 at 23:49
  • 1
    \$\begingroup\$ Not my day. It should work now. \$\endgroup\$
    – Dennis
    Oct 28, 2014 at 0:03
  • 3
    \$\begingroup\$ The first error is still there. But it doesn't have any messages if it is in a script. I think this is acceptable. \$\endgroup\$
    – jimmy23013
    Oct 28, 2014 at 0:07
  • 2
    \$\begingroup\$ @user23013: Interactive tcsh doesn't seem to have comments. \$\endgroup\$
    – Dennis
    Oct 28, 2014 at 0:41

Answer 55 - Pixie; fallback option: ClojureCLR

"//echo o[.>]c;cat<<;#&&alert"(printf
"Hello World!")

Distance 3 from answer 54

The language is in early alpha and seem to have only REPL. Example session:

$ ./pixie-vm 
Pixie 0.1 - Interactive REPL
(linux, gcc)
user => "//echo o[.>]c;cat<<;#&&alert"(printf
//echo o[.>]c;cat<<;#&&alert
user => "Hello World!")
Hello World!user => 

When run outside REPL, I expect it to output just "Hello World!", without additional things.

The language is inspired by Clojure. The script works in Clojure too (without messy additional REPL output)

Here is example of ClojureCLR session (used clojure-clr-1.3.0-Debug-3.5.zip):

$ mono Clojure.Main.exe hello.clj ; echo
Hello World!
  • \$\begingroup\$ (Question "Why 12?") -> Result of printf - 12 bytes outputted. \$\endgroup\$
    – Vi.
    Oct 28, 2014 at 1:31
  • \$\begingroup\$ Is 12 also in the output? If so, it doesn't qualify: "The output should only be Hello World! and no other characters (a leading/trailing newline is not an issue)." \$\endgroup\$
    – Etheryte
    Oct 28, 2014 at 1:38
  • 1
    \$\begingroup\$ 12, //echo o[.>]c;cat<<;#&&alert and user => are printed by REPL, not by the program. But as the language currently have only REPL so far, I can't test in "in real". \$\endgroup\$
    – Vi.
    Oct 28, 2014 at 1:39
  • \$\begingroup\$ I'll say this is allowed since it seems the best Pixie can currently do. But I would prefer you to change the language if possible. \$\endgroup\$ Oct 28, 2014 at 1:45
  • \$\begingroup\$ Note: now Pixie can run the program properly: ./pixie-vm hello.clj -> Hello World!. \$\endgroup\$
    – Vi.
    Dec 11, 2014 at 13:29

Answer 57 - Falcon

//echo o[.>]c;cat<<;#&&alert"(
> "Hello World!"//)

Distance: 7


Answer 65 - Salmon

# %;dnl<vsh  o[.]c;cat;#&&alert" ">w ".( 
"Hello World!"!#bye";dnl</vsh>

Distance 7 from Answer 64


Answer 66 - Turing

%# %;dnl<vsh  o[.]c;cat;#&&alert" ">w ".( 
put "Hello World!" %!#bye";dnl</vsh>

Distance: 7


Answer 72 - AutoLISP

;<vsh  o[.]c;cat;#&&alert" ">w "
(princ "Hello World!");%!#bye";dnl</vsh>~

Distance of 7 from Answer 71 (3 deletions of random stuff).

P.S. For those who argue about invalidity of different dialects of Lisp, you should post on the first dialect..

  • 2
    \$\begingroup\$ I don't think this should qualify as 1) AutoLISP is just a dialect of LISP and 2) it's practically identical to the already existing LISP answer. The question's author will be in a better position to say if it's okay or not though. \$\endgroup\$
    – Etheryte
    Oct 28, 2014 at 18:39
  • 6
    \$\begingroup\$ This will be the 4th version of LISP. Practically identical is not identical, given the princ instead of print. Many many other answers are practically identical, hell, some are even are identical. Where do we draw the line? \$\endgroup\$
    – agweber
    Oct 28, 2014 at 19:10
  • \$\begingroup\$ @agweber The plain Lisp answer also uses princ. The question isn't how similar (or different) it is to other language answers, but to that answer. If we allow answers like this then I got at least 10 identical Lisp dialect answers coming right up. \$\endgroup\$
    – Etheryte
    Oct 28, 2014 at 19:39
  • 1
    \$\begingroup\$ @user3490 yes.. \$\endgroup\$
    – Optimizer
    Oct 28, 2014 at 20:34
  • 1
    \$\begingroup\$ There is no plain Lisp. Answer 48 did not specify which "Lisp". If it was Common Lisp, then there are many Lisps that are not Common Lisp. \$\endgroup\$
    – kernigh
    Nov 21, 2014 at 20:14

Answer 74 - Rebol

;<vsh  o[.]c;cat;#&&alert"  "
print "Hello World!";%!#bye";dnl</vsh>~

Distance from Answer 73 - 7

Anything followed by ; till newline is comment in Rebol


Answer 75 - Maple

#sh  o[.]c;cat;#&&alert"  "print 
"Hello World!";#bye";dnl</vsh>~

Distance 7 from Answer 74.


Answer 78 - ksh

#sh  o[.]c;cat;#&&alert"  "
echo -en "Hello World!"

Distance 7 from Answer 77.


Answer 94 - Processing

//[]([.]c;main()    {
print("Hello World!");

Distance 7 from answer 93

  • \$\begingroup\$ Undeleted again, since it's now clear what answer 93 is. \$\endgroup\$
    – Emil
    Oct 29, 2014 at 20:13

Answer 97 - Dart

main()    {
    print('Hello World!');}

Distance: 7

It's about time we got an #include of some sort.

  • \$\begingroup\$ What will you do with #include ? C answer is already done. \$\endgroup\$
    – Optimizer
    Oct 29, 2014 at 20:35
  • 3
    \$\begingroup\$ @Optimizer include and import both start with i, and lots of languages use them. \$\endgroup\$ Oct 29, 2014 at 20:36

Answer 101 - Alore

--#main()    {
    Print("Hello World!");

Distance 7 from answer 100.

  • \$\begingroup\$ I know, I just commented on this post because it was the latest one at the time that I made the comment, just so that future posters would see it. Sorry if I made it seem like I was commenting on your post specifically. \$\endgroup\$ Oct 30, 2014 at 2:36

Answer 103 - T-SQL

--#main()    {
    Print('Hello World!');

Distance 7 from Answer 102.


Answer 104 - LiveCode

--#main()    {
    put("Hello World!")

should be run from the message box in multiline mode

Distance 7 from Answer 103.


Answer 105 - Euphoria

--#main()    {
puts(1,"Hello World!")

Distance 4 from Answer 104


Answer 106 - SpeakEasy

$ --#[][.]#i--#main()    {puts(1,
"Hello World!"
$ --#[;]#bye;dnl</>"%

Distance from Answer 105 : 7


Answer 111 - TPP

Hello World!

Distance 7 from Answer 110: moved select " to the line above and removed the space (2 deletion2), changed --# to --## on both lines (2), removed the "; from the end of the second line (2), and changed the space between select and " to a newline (1). As my sed post was deleted, I am assuming that I can post without waiting 8 more hours. This doesn't print "Hello World!", but displays it instead. If this is an unsatisfactory answer, let me know.

  • \$\begingroup\$ I count 8. changed the space between select and " to a newline isn't quite what you did. \$\endgroup\$
    – Muqo
    Oct 30, 2014 at 19:12
  • \$\begingroup\$ @Muqo what do you mean? \$\endgroup\$ Oct 30, 2014 at 19:37
  • \$\begingroup\$ Moving select " from the second line to the first line takes 2, and removing the space takes 1. You're counting only 2 (your first step and your fourth step). \$\endgroup\$
    – Muqo
    Oct 30, 2014 at 20:40
  • 1
    \$\begingroup\$ OOPs. I will put back the period and let Timtech know. At least that won't actually break his answer. \$\endgroup\$ Oct 30, 2014 at 21:02
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