Winners Announced in 2026's 'International Obfuscated C Code Competition'

Yesterday 2026's International Obfuscated C Code Contest concluded, with 22 new winners announced in a special three-hour livestreamed ceremony! Started 42 years ago, it's been described as the internet's longest-running contest, with entrants concocting convoluted programs glorying in the C programming language's subtleties, all while having some fun. And "For IOCCC29, the volume and quality of submissions were at near-historic heights," explains its home page.

There's a "Tetris-optimized" GameBoy emulator with source code that looks like a GameBoy, as well as a quasi-Rogue-like game voted "most likely to teleport." Awards were also given for the best imaginary emulator (a virtual machine in 366 bytes of C) and the best fractional emulator (a maze generator for the Commodore 64). But every one of the 22 winning programs seems wildly creative...

• Quine Pong. "Running the program produces the source code to generate the next frame, formatted to display the current frame. By repeatedly compiling and running each successive frame, you can play the game. To move, pass either "w" (up) or "e" (down) as an argument..."

• A winning Taiwanese programmer formatted their source code in the shape of a Tardis from Doctor Who — code that displays an intricate ASCII animation of Doctor Who's 1963 opening title sequence.

• One winning entry emulates an IBM 7040 mainframe, first converting a program (encoded in whitespace) into ASCII-character drawings of punchcards for a FORTRAN program — and then executing that program to calculate the light visible to an observer looking at black hole, ultimately creating an image. It's all recreating what astrophysicist Jean-Pierre Luminet had to do in 1978 to generate the first-ever simulated photograph of a black hole (on an IBM 7040 mainframe). "The entry can also run other FORTRAN programs — but "they must be provided as a deck of punch cards... Tools have been provided to convert to/from decks and to interpret..."

"We have added fun challenges to this year's winning entries competition..." the web site notes. "After you figure out what a given winning entry does, we encourage you to attempt the fun challenge!"

Thanks to long-time Slashdot reader achowe for bringing the news (who has submitted winning entries in four different decades, starting in 1991 and continuing through 2025) — and who won again this year for a program simulating the Space Invaders-like game from Casio's 1980 MG-880 calculator.

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Some wild entries!!

[pele]

But then 42!
So it's nice...

Re:Sad

[HeadSoft]

It does the opposite. It highlights the subtle rules in C that lazy programmers don't always know or care about. You can't write good code if you don't know the rules.

Re:

[achowe]

Knowing the Rules of C is one part, the other is the discipline in coding to avoid the pitfalls that many complain of. Don't let AI/LLM code, since they will be using possibly bugged examples in their training. `C` can continue to out do `Rust` with sufficient discipline - but companies pay for fast, not correct, which is another problem.

Re:

[angel'o'sphere]

Perhaps you should at least start reading up the basics about LLM training.

To spit out buggy code constantly: the training set needs to contain a huge amount of buggy code, in exactly that domain.

In other words: they are in general not trained on buggy code ... unless you want to use it to find bugs.

Re:

[dfghjk]

You are confused, you are thinking of design patterns.

Frilly, not obtuse

[spaceman375]

Sure, there's plenty of fun and humor. But "obfuscate" means to make hidden, unclear, difficult to understand. These are clever parlor tricks at best, made for pretty showings. Nobody is actually reading the code to figure out something subtle and hidden. They just marvel at how pretty the formatting is or the convoluted execution path. It used to all about reading the source, which was written to look normal but hide big surprises, sometimes as poetry. Where are the subtle punctuation marks that completely change a function's behavior, or the occasional whitespace character in a strategic spot? It seems more for artists than programmers now.

Re:

[hey_popey]

Aren't you confusing with the Underhanded C Contest [underhanded-c.org]?

what are you talking about dude

[jizmonkey]

Did you look at the black hole simulation software? That is the craziest fucking thing I have ever seen. Like, I know I'm a better C programmer than 90% of programmers out there but this guy just grinds me into dust with his boot.

Re:

[techno-vampire]

Yes. I remember, years ago, writing a program where I reversed the standard meanings of TRUE and FALSE, not to obfuscate the code (although it did) but so that I could write the one test central to the program in the way that looked right to me. It's a tiny change from what you'd normally use, but most people reading over the code wouldn't even notice it at first and end up completely misunderstanding how it managed to work. To me, at least, that's what the judges should be looking for, rather than odd f

What About perl?

[Princeofcups]

This is yet another way that perl is superior to every other language! Oh wait. (For the record, perl IS the best scripting language for what I do.)

Re:

[dargaud]

As you imply, Perl is naturally obfuscated. I worked in Perl for a year and was so relieved when that was over. I remember as a beginner, I would submit a 20-line piece of slow code and ask for advice on how to improve it, then a better programmer would come up with a 5-line version, then a guru would offer a cryptic 2-line code, and finally an elder god would spew forth a one-liner which would freeze your blood upon decipherment attempt...

Worst abuse of the rules

[Snotnose]

My favorite all time winner got the "Worst abuse of the rules" consisting solely of #include "/dev/kbd"

Re:

[gmiller123456]

It was #include "/dev/tty", and definitely my favorite too.

shoot

[dehachel12]

are the winners put in front ofa firing squad ?