PPMZ has long been the best algorithm for lossless compression. I publish here an analysis of the algorithm and why it works so well. Published here in March, 1998. Several new techniques are presented on high order context modeling, low order context modeling, and order-0 arithmetic coding. Emphasis is placed on economy of memory and speed.
Performance is found to be significantly better than previous methods.
This coder is interesting primarily only for theoretical reasons, not for its efficiency.