isr.co.ro : glossary Gzip A Unix compression utility developed by the Free Software Foundation as part of its GNU project for developing alternatives to commercial versions of Unix. It is a "lossless compression" method, meaning files that are decompressed should be bit-for-bit copies of the original. Files compressed with gzip are usually marked with a suffix of ".gz." While gzip compression is usually done only on Unix machines, you'll find utilities that will decompress .gz files on most other computer systems.