TL;DR
The 2025 IOCCC winners were announced after a record-high number of submissions. Notable entries include a Subleq computer, a black hole punchcard, and a GameBoy emulator. The contest continues to celebrate creative obfuscation in C programming.
The winners of the 29th International Obfuscated C Code Contest (IOCCC) for 2025 have been officially announced, with notable entries such as a Subleq computer, a black hole punchcard, and a GameBoy emulator. The announcement follows a rigorous judging process that assessed a record number of submissions, highlighting the contest’s ongoing relevance in showcasing programming creativity and obfuscation techniques.
The IOCCC29 judging panel revealed the winning entries on the Our Favorite Universe YouTube channel, with the full list of winners now available on the official contest website. This year’s contest attracted a high volume of submissions, comparable to previous years, despite a four-year hiatus that ended in 2020. The entries ranged from highly innovative code to complex puzzles, with some authors returning for multiple wins. Notable winners include Yusuke Endoh, Nick Craig-Wood, Don Yang, and first-time winner jingp49 from Taiwan.
Key winners include 2025/cable, a Subleq computer; 2025/cesmoak, a black hole punchcard Fortran; 2025/endoh3, a patch/diff quine; 2025/jhshrvdp, a quasi-rogue-like game; and 2025/ncw1, a GameBoy emulator. The contest also introduced fun challenges for participants to further analyze or improve upon the winning entries, encouraging community engagement and collaboration.
Why It Matters
The IOCCC remains a prominent platform for showcasing advanced obfuscation techniques and programming ingenuity, influencing both hobbyist and professional coding communities. The high quality and diversity of submissions demonstrate ongoing interest and skill in complex code design. The contest’s emphasis on creativity and technical mastery fosters innovation in programming practices, with potential applications in security, code compression, and educational tools.
Moreover, the contest’s public recognition and documentation efforts help preserve unique coding styles and serve as educational resources for understanding advanced C programming concepts. The announcement underscores the importance of preserving and promoting creative coding as a form of technical art and intellectual challenge.
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Background
The IOCCC, established in 1984, has long celebrated the art of obfuscated programming in C. After a four-year hiatus from 2020 to 2024, the contest resumed in 2025 with increased participation, likely driven by improved outreach, social media presence, and community interest. Previous winners include renowned programmers and obfuscation experts, and the contest has historically attracted entries that push the boundaries of code readability and complexity.
This year’s contest saw entries from around the globe, including a first-time winner from Taiwan, reflecting its international appeal. The judging process was documented in detail, with a focus on transparency and community involvement, including the addition of fun challenges to engage participants further.
“The 2025 contest saw a remarkable increase in submission quality and diversity, reaffirming the IOCCC’s role as a hub for creative coding.”
— IOCCC Judge Team
“Winning entries demonstrate that obfuscation can be both an art and a technical challenge, pushing the limits of what C code can do.”
— Yusuke Endoh
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What Remains Unclear
While the winners have been announced, detailed analyses of each entry’s functionality and the judging criteria are still being published. The full impact of the new rules and the influence of recent submissions remain to be assessed, and community feedback on the contest’s direction is ongoing.
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What’s Next
The IOCCC team plans to open submissions for the 30th contest towards the end of 2026, with judging and announcement scheduled for early 2027. The organizers also intend to document the process further and encourage community participation through challenges and collaborative improvements on existing entries.
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Key Questions
What are some of the most notable entries of the 2025 IOCCC?
Highlights include a Subleq computer, a black hole punchcard for Fortran, a patch/diff quine, a quasi-rogue-like game, and a GameBoy emulator, among others.
How does the judging process work for the IOCCC?
The judging involves evaluating entries based on complexity, originality, and obfuscation quality, with a panel of experts reviewing submissions and providing feedback. Detailed criteria are published post-competition.
Can community members contribute or improve upon winning entries?
Yes, the contest encourages submissions of improvements or alternative solutions through GitHub pull requests, which are considered by the judges if deemed superior.
When will the next IOCCC contest be held?
The next contest, IOCCC30, is planned to open in late 2026, with submissions closing in early 2027.
Source: Hacker News
