zlib

Massively used compression library

Critical · 31/100

Automated health estimate

The score summarizes repository activity. Funding is unknown and excluded from the score. These repository signals do not establish financial stability, security, or maintainer availability. How to interpret this data.

Funding

Unknown

Maintenance

Inactive

Contributors

Some observed

Bus Factor

High risk

Metrics last updated: today (2026-10-25)

Evidence and limitations

Activity source: madler/zlib via the GitHub API. Counts describe this repository, which may be a mirror or only part of the project.

Commits in 30 days: 0
Commits in 90 days: 24
Authors accounting for half the sampled commits: 1

The sampled commit history reached the 90-day boundary or the end of the repository history.

Few commits can reflect mature software. Commit authors do not establish merge rights, available maintainers, organizational diversity, or knowledge distribution. Funding is unknown; donation links alone do not establish income or runway.

Correct this assessment or provide evidence →

Ways to help zlib

The zlib website directs development contributions and issues to its GitHub repository. We have not verified a project donation route.

Prepare a zlib issue or contribution
Read the FAQ and manual first, then use the development repository for a reproducible issue or proposed change.

Official sources checked 2026-10-02. zlib project website. These are public participation routes, not a maintainer-confirmed urgent request.

People associated with this project

Profiles include creators, contributors, and former maintainers. This is not a complete roster of the current team.

Mark Adler

zlib Co-Creator

Overview

zlib is a software library used for data compression. It is one of the most widely deployed libraries in existence, found in virtually every operating system and countless applications.

Importance

Used by PNG, gzip, HTTP compression, and countless formats
Embedded in Python, Java, .NET, and most programming languages
Critical dependency for package managers and web servers
Foundation of modern data compression on the internet

Key Features

Fast compression and decompression
Portable C implementation
In-memory compression
gzip file format support

Sustainability

The zlib website directs development contributions and issues to its GitHub repository. We have not verified a project donation route. zlib project website.

Source pages checked 2026-10-02. Financial capacity has not been independently assessed.