Apparently these are called "ouroboros programs". http://asiajin.com/blog/2009/09/22/uroboros-programming-with-11-programming-languages/ http://asiajin.com/blog

Apparently these are called "ouroboros programs". http://asiajin.com/blog/2009/09/22/uroboros-programming-with-11-programming-languages/ http://asiajin.com/blog/2009/09/22/uroboros-programming-with... (which serves an empty page to me right now) used to have a period-11 cycle of programs. I wrote a period-3 program (http://www.stratigery.com/source.html#Ouroboros http://www.stratigery.com/source.html#Ouroboros).