TL;DR
The 29th IOCCC announced its winners on YouTube, featuring notable entries like a Subleq computer and a GameBoy emulator. The contest saw high-quality submissions after a four-year hiatus. Next steps include opening IOCCC30 in late 2026.
The winners of the 29th International Obfuscated C Code Contest (IOCCC) were announced on YouTube, showcasing a diverse array of highly complex and creative C programs. This marks the first full reveal since the contest concluded in late 2024, with the winners selected from a record-high volume of submissions from around the globe. The announcement underscores the contest’s ongoing relevance and the increasing sophistication of obfuscated coding techniques.
The IOCCC 2025 winners were revealed through a series of YouTube segments, each linked from the official contest website. Notable entries include a Subleq computer emulator, a black hole punchcard Fortran program, a patch/diff quine, and a GameBoy emulator, among others. The contest received a high volume of submissions comparable to the previous year, despite a four-year hiatus, with many authors building on past ideas and leveraging improved online outreach.
Among the winners, new author jingp49 from Taiwan was recognized, marking a rare international addition to the list of winners. The contest also celebrated repeat winners, such as Yusuke Endoh, Nick Craig-Wood, and Don Yang, each achieving hat-tricks of winning entries. The judging process involved detailed review and documentation, with the final results now publicly accessible via the contest’s website and YouTube.
Why It Matters
This announcement highlights the ongoing vitality of the obfuscated C coding community, which continues to push technical boundaries and creativity. The high quality and diversity of entries demonstrate the contest’s role in fostering innovative programming techniques and community engagement. For developers, researchers, and enthusiasts, the contest provides insights into advanced code obfuscation, optimization, and problem-solving strategies, making it a valuable resource for both education and experimentation.
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Background
The IOCCC, established in 1984, has historically served as a platform for showcasing the most intricate and inventive uses of C programming. After a four-year hiatus from 2020 to 2024, the 2025 contest marked a significant return, with increased online presence and a larger pool of submissions. Previous contests have seen record participation, and 2025 maintained this trend despite the gap, suggesting renewed interest and engagement within the community. The contest’s rules and judging procedures were updated in 2025, emphasizing transparency and encouraging innovative approaches.
“The 2025 submissions demonstrated exceptional creativity and technical skill, reflecting a vibrant community eager to push the limits of obfuscation.”
— IOCCC Judge
“Winning these awards motivates me to explore even more complex and interesting ways to write obfuscated code.”
— Yusuke Endoh
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What Remains Unclear
While the winners have been announced and detailed descriptions are available online, the specific criteria used for judging some entries remain internal. Additionally, the full impact of the contest on future obfuscated C programming trends is still developing, and the community’s response to the new rules and guidelines is ongoing.
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What’s Next
The IOCCC organizers plan to open submissions for the 30th contest towards the end of 2026, with a deadline set for early 2027. They also intend to document the process more thoroughly and encourage community participation through fun challenges and potential improvements to submission formats. Following the announcement, the community will analyze the winning entries further and consider possible enhancements for future contests.
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Key Questions
Who were the notable winners of IOCCC 2025?
Notable winners include a Subleq computer emulator, a black hole punchcard Fortran program, a patch/diff quine, and a GameBoy emulator. Several repeat winners also achieved multiple awards, with one new author from Taiwan making a debut.
How were the winners announced?
The winners were revealed through a series of segments on the Our Favorite Universe YouTube channel, with links provided on the contest website for each winning entry.
What are the plans for the next IOCCC?
The next contest, IOCCC30, is scheduled to open in late 2026, with submissions closing in early 2027. The organizers plan to continue documenting the process and engaging the community through challenges and updates.
How can I view the winning entries?
All winning entries and their detailed descriptions are available on the IOCCC official website, with video segments linked from the contest’s YouTube channel.
Source: Hacker News
