Install zpaq with Homebrew, apk, apt, dnf, MacPorts, Nix, zypper

Project links

• Homepage
• Repository

Commands and aliases

• zpaq

Project history

The official ZPAQ page traces readable archive compatibility back to version 1.00 in March 2009. The early format was a streaming archive format; version 5.00 in August 2012 added a level-2 format for compression with pre/post processing, version 6.00 in September 2012 introduced the journaling format with deduplication and rollback, and January 2014 versions added encryption and multipart archives.

ZPAQ belongs to Matt Mahoney's broader PAQ compression lineage. Its distinctive format design stores decompression code in a sandboxed virtual machine language called ZPAQL, which helps newer compression methods remain extractable by older readers when the archive only needs supported format features.

The final upstream package advertised on the official page is zpaq v7.15, released in August 2016, containing C++ source, libzpaq, documentation, Windows binaries, and a Makefile for Unix-like systems. The page presents ZPAQ as public-domain software and an open standard rather than a proprietary backup container.

Adoption history

ZPAQ never became as mainstream as zip, 7-Zip, or RAR, but it earned a durable niche among compression and backup users because it solved repeated-backup storage differently from one-shot archivers. The official page compares it against backup and archiving tools and emphasizes realistic backup workloads with duplicate and already-compressed files.

The batch package metadata shows ZPAQ packaged in Homebrew, Debian, Ubuntu, Fedora, Alpine, MacPorts, Nix, and openSUSE. That broad Unix packaging footprint reflects a tool valued by technically minded users even after upstream development slowed.

How it is used

Typical usage is `zpaq add archive.zpaq files` for incremental backups and `zpaq extract archive.zpaq path -until DATE_OR_VERSION` to restore old states. Updates append new archive data instead of overwriting old versions, and interrupted transacted updates are ignored or overwritten on the next update.

ZPAQ is best understood as a user-level backup and archival tool. The official documentation warns against using it for complete operating-system backups and lists filesystem metadata that it does not preserve, such as ACLs, owner/group IDs, registry data, and special device files.

Why package nerds care

ZPAQ matters to package nerds because it is both a CLI and a format study: append-only backups, content-defined chunking, SHA-1 fragment deduplication, optional encryption, multipart remote archive workflows, and a published decoder specification in one small tool.

It is also a good example of a high-compression research lineage surviving as a practical package. Users install `zpaq` not because it is fashionable, but because no ordinary archive format quite has the same combination of journaling history and deduplicated backup behavior.

Timeline

• 2009-03: ZPAQ v1.00 establishes the level-1 streaming archive format.
• 2012-08: ZPAQ v5.00 adds the level-2 format with pre/post processing.
• 2012-09: ZPAQ v6.00 adds the journaling format with deduplication and rollback.
• 2014-01: ZPAQ v6.44 adds encrypted archives.
• 2014-01: ZPAQ v6.47 adds multipart archive support.
• 2016-08-17: ZPAQ v7.15 is released on the official site.

Related projects

• PAQ, PAQ8, LPAQ, and related Matt Mahoney compression projects are the research family around ZPAQ.
• libzpaq is the C++ compression/decompression library shipped with ZPAQ.
• zpaqfranz is a later fork that extends the ZPAQ backup idea for more operational disaster-recovery use cases.

Sources

• https://mattmahoney.net/dc/
• https://mattmahoney.net/dc/zpaq.html
• input.json source_facts.package-manager