Lempel-Ziv-Oberhumer

Lempel-Ziv-Oberhumer, usually abbreviated LZO, is a lossless data compression algorithm focused on decompression speed. The original lzop implementation, released in 1996, was developed by Markus Franz Xaver Johannes Oberhumer, based on earlier algorithms by Abraham Lempel and Jacob Ziv. The LZO library implements several algorithms that share these properties: higher compression speed than DEFLATE, very fast decompression, a small extra buffer of 8 kB or 64 kB during compression, no additional memory for decompression beyond the source and destination buffers, and an adjustable balance between compression ratio and compression speed that does not affect decompression speed. As a block compression algorithm it compresses blocks of data into matches against a sliding dictionary and runs of literal bytes, and it expands incompressible data by at most 1/64 of its original size over blocks of at least 1 kB. The reference implementation is written in ANSI C under the GNU General Public License, and the Linux kernel uses LZO in btrfs, initramfs, SquashFS, zram and zswap.