# nih-at/libzip

A C library for reading, creating, and modifying zip archives.

Repository: https://github.com/nih-at/libzip
Canonical: https://ross.abutalabs.com/products/libzip
Homepage: https://libzip.org/
Language: C
License: NOASSERTION
License Family: other
Topics: zip, library, archive, encryption, compression
Last push: 2026-08-30T08:31:42+00:00

## Health v2 (maintenance only)
Score: 75/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 100, release rhythm 28, longevity 100
- inputs: {"age_days": 3850, "days_push": 3, "days_rel": 467, "gap_med": 61.0, "n_releases_24m": 5}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1045, forks 336 (observed 2026-09-01T02:14:05.318906+00:00)

## What it is
libzip is a C library for reading, creating, and modifying zip archives, with support for Zip64, multiple compression codecs (deflate, bzip2, LZMA, zstd), and Winzip AES/PKWARE encryption. It ships with command-line tools (ziptool, zipcmp, zipmerge) and has bindings for Python, Ruby, Lua, and PHP.

## Use cases
- read and extract zip archives in a C or C++ application
- create zip files programmatically with compression
- modify existing zip archives without corrupting them
- handle encrypted zip archives with AES or PKWARE encryption
- work with large zip64 archives
- compare or merge zip archives from the command line

## When to choose
- you need a mature, stable C library for zip manipulation with a backwards-compatible API
- you need encryption, Zip64, or multiple compression algorithm support
- you want a small, efficient library usable in commercial products under a BSD license
- you need cross-platform support across Linux, macOS, and Windows

## When to avoid
- you need to handle archive formats other than zip, like tar or 7z
- you are working in a language with a native zip library and don't want a C dependency
- you need a high-level object-oriented API rather than a C API

## Facets
- artifact type: library
- maturity: stable
- function: compression, file-system, cryptography, cli
- domain: files, developer-tools, cross-platform
- platform: windows, cpp, c, cross-platform, cli
- tags: zip, archive, zip64, encryption, bsd-license, language-bindings, linux, macos

## Member repositories
- nih-at/libzip (main) score 75

## Provenance
- Observed fields: from GitHub, fetched 2026-09-01T02:14:05.318906+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T07:02:31.141936+00:00, confidence not recorded.
  - readme: https://github.com/nih-at/libzip (fetched 2026-09-01T02:14:05.318906+00:00, sha d7376fdd7ed3)
  - homepage: https://libzip.org/ (fetched 2026-08-29T13:03:28.357874+00:00, sha 691ba6ecf2ec)
  - site_page: https://libzip.org/documentation (fetched 2026-08-29T13:03:28.361413+00:00, sha 0e6e51bee601)
- Data as of 2026-08-30T08:39:29.467469+00:00.