ZLIB, DEFLATE, and GZIP documentation

RFC 1950: ZLIB 3.3 specification

• Abstract: This specification defines a lossless compressed data format. The data can be produced or consumed, even for an arbitrarily long sequentially presented input data stream, using only an a priori bounded amount of intermediate storage. The format presently uses the DEFLATE compression method but can be easily extended to use other compression methods. It can be implemented readily in a manner not covered by patents. This specification also defines the ADLER-32 checksum (an extension and improvement of the Fletcher checksum), used for detection of data corruption, and provides an algorithm for computing it.

RFC 1951: DEFLATE 1.3 specification

• Abstract: This specification defines a lossless compressed data format that compresses data using a combination of the LZ77 algorithm and Huffman coding, with efficiency comparable to the best currently available general-purpose compression methods. The data can be produced or consumed, even for an arbitrarily long sequentially presented input data stream, using only an a priori bounded amount of intermediate storage. The format can be implemented readily in a manner not covered by patents.

RFC 1952: GZIP 4.3 specification

• Abstract: This specification defines a lossless compressed data format that is compatible with the widely used GZIP utility. The format includes a cyclic redundancy check value for detecting data corruption. The format presently uses the DEFLATE method of compression but can be easily extended to use other compression methods. The format can be implemented readily in a manner not covered by patents.

• SWRI, Texas
• JPL, California
• ISI, California
• WUarchive, StLouis
• ftp.ds.internic.net
• Toronto, Canada
• Great Britain
• Vienna, Austria (mirror of SWRI)
• Denmark
• Italy
• South Africa
• Russia
• Australia
• IIJ, Japan
• NECTEC, Thailand
• ftp.uu.net (mirror of SWRI)