A comprehensive emulator of MMIX, a hypothetical 64-bit RISC CPU, used in The Art of Computer Programming. This emulator was written by Donald Knuth himself in CWEB, a C-variant.

It emulates all the details of the computer, like pipelines, implementation of complex instructions, out-of-order execution, branch prediction, caches and TLBs. Various parameters, like cache size and associativity, number of execution units and their throughput and latency, can be configured. Because it tries to emulate the way modern CPUs actually work, the resulting timing will more accurately reflect real-world situations.

It is a great education tool for people interested in some new technologies employed in modern CPUs.

Also called mmix-pipe.