I'm fuzzy on the history, but I believe that modern Xinu is actually a complete rewrite since sometime in the early 2000s (the linked page says "ports the code

I'm fuzzy on the history, but I believe that modern Xinu is actually a complete rewrite since sometime in the early 2000s (the linked page says "ports the code to the x86 architecture " again in 2010-2011). In 2014 Dr. Comer had taped to his office door a sheet of project ideas for grad students, one of them was adding virtual memory support to Xinu.