Great news! Problem of the Day is now open source.

This site got its start back in the beginning of March and quickly took to the top of /r/programming. After over 140 problems its great to see the site still growing with more and more users contributing solutions to problems. By open sourcing the site the community can now not only solve problems together but also contribute back to growing itself. I look forward to seeing this site grow in to the destination for problem solvers. If you're looking for ways to contribute back please checkout the Github issues or get in contact with me about areas you can help with.

If you're looking for a problem to work on today head back in time to the one that started it all, cracking the Vigenère cipher.