Earlier editions of the book use the original MIX. MMIX has little in common with its predecessor MIX, which was conceived in the 1960s.
Literature: Donald E. Knuth (Heidelberg: Springer-Verlag, 1999), viii+550pp. MMIXware A RISC Computer for the Third Millennium
(Lecture Notes in Computer Science, no. 1750.[1] (http://link.springer.de/link/service/series/0558/tocs/t1750.htm))
MMIX is also the Roman numeral for the year 2009.
wikipedia.org dumped 2003-03-17 with terodump