The Lempel–Ziv–Markov chain algorithm (LZMA) is an algorithm used to perform data compression. It has been under development since 1998 and is used in the 7z format of the 7-Zip archiver. This algorithm uses a dictionary compression scheme somewhat similar to LZ77 and features a high compression ratio (generally higher than bzip2) and a variable compression-dictionary size (up to 4 GiB). p7zip uses lzma compression.