Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv (LZ77) and Huffman coding. The program was created by Jean-Loup Gailly and Mark Adler as a free software replacement for the compress program used in early Unix systems, and intended for use by the Project. Version 0.1 was first publicly released on October 30, 1992, and version 1.0 followed in February 1993.