IOCCC Returns After Hiatus with Record-Breaking Entries, AI Struggles to Keep Up
The International Obfuscated C Code Contest (IOCCC) made a triumphant return after a four-year pause, attracting a record-breaking 23 winning submissions thanks to an unusually high caliber of entries. The contest, a celebrated tradition in the programming world, showcases the ingenuity and skill of C language experts, with this year’s projects ranging from a salmon recipe hidden within invisible Unicode characters to a nostalgic “Rickroll” delivered via an 8-bit port of an Atari 2600 game.
The winning entries demonstrated a mastery of the C language, pushing the boundaries of what’s possible with the decades-old programming language. One particularly striking example involved a program that, despite appearing innocuous, printed a complete recipe for grilled salmon – achieved through the clever use of hidden Unicode characters. Another entry cleverly resurrected a classic internet prank, “Rickrolling” the judges with a faithful recreation of the 1987 music video.
Judges, including IOCCC founder Landon Curt Noll, experimented with Large Language Models (LLMs) to analyze the complex code, but found the results inconsistent. Ultimately, human judgment prevailed, with LLMs proving unable to fully grasp the intricacies of the obfuscated submissions. “For some entries, the LLMs were able to have a guess what the entry does, just based on the overall code structure or whether it uses logic with math… And for some entries, it was completely clueless,” a judge noted.
The contest’s return also highlighted the continued superiority of human programmers over current AI models. One contestant even crafted a fully functional 750-byte LLM inference engine – a feat Noll believes is beyond the reach of contemporary AI. “I don’t think any model any time soon is going to be able to produce code that good!” he stated. However, judges suggested LLMs could be a useful tool for contestants, helping them assess the difficulty of their obfuscation techniques.
This year’s contest also marked the revival of a live winner announcement, a tradition dating back to the 1980s. The modern presentation, spearheaded by David McInnis, featured videos showcasing the outputs of the winning entries, a significant upgrade from Noll’s original method of projecting transparencies. The organizers also noted that the hiatus likely allowed contestants more time to refine their submissions, resulting in the unprecedented number of high-quality entries. “We really couldn’t come up with a good justification for leaving some of these really amazing winning entries out!” Noll explained.
The judges opted not to award a “Best of Show” or “Grand Prize,” acknowledging the exceptional quality across the board. Beyond the Rickroll and the salmon recipe, another standout entry came from Yusuke Endoh, whose program generated beautiful ASCII animations of spinning objects, accurately simulating the physics of a rotating rigid body. Endoh further enhanced the visual effect by strategically spacing the code itself to form the image of a spinning top.
All winning source code, including the infamous “Rickroll,” is now publicly available on a dedicated GitHub repository. The IOCCC is already planning its next iteration, with registration anticipated to open in December 2025. Organizers intend to update the entry packaging tools and refine the contest rules based on their experience with this year’s event.
As the judges look ahead, they emphasize the importance of human creativity and skill in the realm of programming. “The people that wrote these programs put a lot of effort and skill. They are masters of the C language. And they’re masters at presenting it and getting it into a small chunk!” Noll affirmed. After years of dedication, the judges are now looking forward to a well-deserved vacation, promising to return with renewed energy for the next chapter of the IOCCC. “It’s time for us to enjoy the results of the authors of the winning entries, and take a break,” Noll concluded. “Enjoy the winning entries of IOCCC28. They’re amazing, and we’re really pleased to present those to you!”
