liblzma is a public domain general-purpose data compression library with a zlib-like API. The native file format is .xz, but also the old .lzma format and raw (no headers) streams are supported. Multiple compression algorithms (filters) are supported. Currently LZMA2 is the primary filter.

liblzma is part of XZ Utils https://xz.tukaani.org/xz-utils/. XZ Utils includes a gzip-like command line tool named xz and some other tools. XZ Utils is developed and maintained by Lasse Collin and Jia Tan.

Major parts of liblzma are based on Igor Pavlov's public domain LZMA SDK https://7-zip.org/sdk.html.

The SHA-256 implementation is based on the public domain code found from 7-Zip https://7-zip.org/, which has a modified version of the public domain SHA-256 code found from Crypto++ https://www.cryptopp.com/. The SHA-256 code in Crypto++ was written by Kevin Springle and Wei Dai.