About SIO2

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SIO2 is a free platform for carrying out algorithmic contests.

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Young and old, students and professionals from all around the world enjoy programming contests. These contests, with problems usually algorithmic in nature, help boosting abstract thinking, developing a confident attitude towards challenging tasks and they give a lot of fun. Programming competitions are frequently used by IT companies for selecting the best and brightest candidates to hire.

Organizations such as ACM International Collegiate Programming Contest, International Olympiad in Informatics or TopCoder are known to almost every IT student and many HR departments. And there are many more.

Until now, every single contest organizer had his own proprietary — frequently being a big blob of muddy code — contest system, web interface, automatic submissions grader etc. SIO2 is an easy, all-in-one platform for contest organizers. And it's completely free! SIO2 is The System for running programming contests.


  • Free and Open Source
    SIO2 is free to download and use. It is distributed under the GNU GPLv3 license.
  • Easy administration
    Setting up a contest is just a matter of a few clicks in a convenient web interface.
  • Safe and distributed grading
    Solutions are executed in a special, safe environment and can be distributed to multiple judging machines for larger contests.
  • Multiple contests simultaneously
    As many contests as you wish may be carried out at the same time.
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