# icsharpcode/SharpZipLib

ziplib is a Zip, GZip, Tar and BZip2 library written entirely in C# for the .NET platform.

Repository: https://github.com/icsharpcode/SharpZipLib
Canonical: https://ross.abutalabs.com/products/sharpziplib
Homepage: http://icsharpcode.github.io/SharpZipLib/
Language: C#
License: MIT
License Family: permissive
Last push: 2024-09-03T21:00:32+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5849, "days_push": 729, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3930, forks 1007 (observed 2026-08-28T04:08:29.946242+00:00)

## What it is
SharpZipLib is a pure C# compression library for .NET supporting Zip (stored/deflate, PKZIP and AES encryption, Zip64), GZip, zlib, raw deflate, Tar, and BZip2 formats. It ships as a NuGet package and can be used from any .NET language without native dependencies.

## Use cases
- create and extract zip archives in C#
- compress files with gzip in .NET
- read tar archives with long filenames
- password-protect zip files with AES encryption
- decompress bzip2 streams in .NET
- handle zip64 archives larger than 4GB

## When to choose
- you need zip/gzip/tar/bzip2 support in pure managed .NET code without native DLLs
- you need AES-encrypted or Zip64 archives
- you want a mature MIT-licensed compression library for .NET

## When to avoid
- you need Deflate64 support
- you only need basic zip handling and prefer the built-in System.IO.Compression
- you need formats like 7z or RAR

## Facets
- artifact type: library
- maturity: stable
- function: compression, file-system, cryptography
- domain: files, developer-tools, cross-platform
- platform: dotnet, cross-platform
- tags: zip, gzip, tar, bzip2, c-sharp, archive

## Member repositories
- icsharpcode/SharpZipLib (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:29.946242+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 2026-08-29T18:24:41.620199+00:00, confidence not recorded.
  - readme: https://github.com/icsharpcode/SharpZipLib (fetched 2026-08-28T04:08:29.946242+00:00, sha 9ad70641b2ba)
  - homepage: http://icsharpcode.github.io/SharpZipLib/ (fetched 2026-08-29T09:18:27.360083+00:00, sha fa11fb492e12)
- Data as of 2026-08-30T08:39:29.467469+00:00.