From an article in the techdirt web site:

Join our public domain game jam, Gaming Like It’s 1928! »

Happy new year, everyone — and happy public domain day! That’s right: today’s the day that works from 1928 exit copyright protection and become public domain in the US, and that means it’s time for the latest edition of our annual public domain game jam, Gaming Like It’s 1928! We’re calling on designers of all stripes and all levels of experience to put this year’s newly public domain works to use in digital and analog games.