LZMA

LZMA is a lossless data compression algorithm developed by Igor Pavlov. It is widely used in the 7-Zip software and in the XZ family of compression formats. The abbreviation stands for Lempel-Ziv-Markov chain algorithm, reflecting its origins in the LZ77 family and its use of a probabilistic model to predict and encode data.

The core design combines a large sliding-window dictionary with a range encoder and adaptive context models. Data is encoded as literals or length/distance match references, with long-distance matches and variable-length codes enabling high compression ratios. The encoder is memory-intensive and relatively slow to compress, while decoding is typically fast.

Usage and impact: LZMA is a standard choice when high compression ratio is desired, especially for executables, archives, and scientific data. It is implemented in libraries and utilities across many platforms and forms a core component of 7-Zip archives and XZ-compressed files.

See also: Lempel-Ziv, LZ77, range coder, XZ Utils, 7-Zip.