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.