28th International Obfuscated C Code Contest

Summary

Twenty Eighth International Obfuscated C Code Contest Where to start See below for links to the 2024 winning IOCCC entries. Check out the index.html web pages for each winning entry. They have most of the information you need to compile and run the winning program. Take a look at the winning source code and try to figure out how it works. You might also want to check out the author’s remarks for even more details. You may download all winning entries in the form of a compressed tarball, for this year’s contest. This year marked the 40th anniversary of the IOCCC. The IOCCC28 opened submissions from 2025-03-05 23:19:17.131107 UTC to 2025-06-05 04:03:02.010099 UTC after a 4 year pause. A significant portion of those 4 years was an effort by a number of people, with over 6168+ commits, to rebuild the Official IOCCC website in what became known as the Great Fork Merge. Another portion of those 4 years went into retooling the IOCCC, including the creation of the mkiocccentry toolkit, a new IOCCC registration process, and a new IOCCC submit server (which may not be up if the contest is closed). The major motivation for the above was to: Present IOCCC winners that that honors the contributions of all of the winning authors from around the world, Reduce the administrative effort required by the IOCCC Judges to run the contest, and Minimize the time between when the winners of the IOCCC are selected and when the source is made available. On the last point, for IOCCC28 the Judging started on 2025-06-05 04:03:02.010099 UTC and then the winners were selected by the IOCCC Judges on 2025-07-07 20:05:07.000000 UTC: No longer will there be many months between when the winners are announced and their source code is made available. For IOCCC28 the time was less than 2 hours. :-) Increased submission quantity and quality The submissions to IOCCC28 were remarkable when compared with previous contests, in both the increased quantity and quality of the submissions. As a result the judging...