There are no physical MIX computers, yet. MIX is a hypothetical, instructional computer construct, a virtual computer in a book, invented and intended to teach fundamental and low level computer programming, via algorithms. MIXAL is an acronym for MIX Assembly Language, an instructional language, for use with the MIX computer. MIX and MIXAL were first defined in Donald Knuth's highly influential and acclaimed: The Art of Computer Programming (TAoCP), Vol. 1: Fundamental Algorithms, Addison-Wesley, 1973. The books in the Art of Computer Programming series are widely viewed as the most important computer programming texts ever written. All programming examples in the series are written in MIXAL. MIX is an example of an old style CISC (Complex Instruction Set Computer) processor, and is somewhat dated. Knuth is replacing the MIX architecture with a modern 64-bit RISC (Reduced Instruction Set Computer) variant named MMIX, and new language named MMIXAL. While this all started as a book, a growing body of software implements MIX emulators, MIXAL, and MMIX. Interest in this topic is growing. Someday will there be physical MMIX computers?