1950: ZLIB Compressed Data Format Specification version 3.3.

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.