grzip is a high-performance file compressor based on Burrows-Wheeler
Transform, Schindler Transform, Move-To-Front, and Weighted Frequency
Counting. It uses the Block-Sorting Lossless Data Compression Algorithm,
which has received considerable attention in recent years for both its
simplicity and effectiveness. This implementation has a compression rate
of 2.234 bps on the Calgary Corpus (14 files) without preprocessing
filters.

WWW: http://BSDforge.com/projects/archivers/grzip