Install lzsa with Homebrew, Nix

Project links

• Homepage
• Upstream docs
• Package manager page

Commands and aliases

• lzsa

Project history

LZSA is not a general Unix compressor in the gzip tradition. It is a modern tool built for old hardware constraints: small decompressors, simple byte-aligned decoding, limited 8-bit arithmetic, and assets that must unpack quickly on Z80, 6502, 8088, 6809, 6309, and related targets.

The repository combines a command-line compressor, formal stream/block format documents, benchmark comparisons, and contributed assembly depackers. Releases through the 1.3 and 1.4 series focused on ratio improvements, faster LZSA2 compression, and a growing collection of platform-specific depackers.

Adoption history

LZSA's adoption is concentrated in retrocomputing, demoscene, and homebrew game development rather than mainstream system archives. The official README lists concrete uses including ZX Spectrum demos, Apple II projects, Commander X16 ROM work, RomWBW, rasm-compressed data sections, and Amstrad CPC game assets.

Package-manager adoption is correspondingly smaller than LZ4 or lzip. The input package facts show Homebrew and Nix packages, enough to make the compressor easy to install on developer machines even though the decompression targets are often vintage CPUs.

How it is used

Developers run the lzsa tool on modern systems to pack assets, then include the matching depacker on the target machine. The key choice is not just compression ratio but the decompressor's speed and code size on a specific CPU.

The upstream format documentation supports implementers who need to write or audit their own depackers, which is common in size-constrained retro projects.

Why package nerds care

LZSA is package-nerd significant because it is a niche tool with real cross-compilation value: the package runs on modern macOS/Linux build hosts but exists to feed 8-bit runtime environments.

It also shows a different kind of compression packaging pressure. For LZSA, the artifact that matters may be a 67-byte Z80 depacker or a 6502 speed-optimized routine, not a shared library ABI.

Timeline

• 2010s: LZSA appears as a retrocomputing-focused compressor and format family.
• 2019-2020: Upstream README records use in demos, games, and ROM projects across Z80, 6502, and related systems.
• 2023: GitHub releases include the 1.4.x series, continuing performance and depacker work.

Related projects

• LZ4 is an explicit design reference for LZSA1.
• ZX7 is an explicit comparison point for LZSA2.
• Lizard/LZ5 and other optimal packers appear in upstream comparisons.

Sources

• https://github.com/emmanuel-marty/lzsa
• https://github.com/emmanuel-marty/lzsa/blob/master/BlockFormat_LZSA1.md
• https://github.com/emmanuel-marty/lzsa/blob/master/BlockFormat_LZSA2.md
• https://github.com/emmanuel-marty/lzsa/blob/master/StreamFormat.md
• https://github.com/emmanuel-marty/lzsa/releases
• source_facts.package-manager