# Unicorn

Rack HTTP server for Ruby applications on Unix-like systems, run as a master process that manages forked worker processes.

STUB. This software has no release or pre-release in four years, or its project site no longer shows it, so it is not part of the register, not counted and not indexed. It will be checked again.

Source: https://findsoftware.frbit.cloud/unicorn/
Last reviewed: 2026-10-30
Listed since: 2026-10-30

## Record

### Links

- home: https://yhbt.net/unicorn/
- repository: https://yhbt.net/unicorn.git
- docs: https://yhbt.net/unicorn/README
- forum: https://yhbt.net/unicorn-public/

### Identity

- status: stub
- maintainer: unicorn contributors
- maintainerType: community
- parent: unknown
- firstRelease: 2009
- hqCountry: unknown

### Kind

- category: web-server
- hosting: ruby
- language: unknown
- runtime: ruby
- runtimeMin: ruby 2.0
- basedOn: unknown

### Content

- contentStore: not applicable
- databases: not applicable
- adminUi: not applicable
- headlessApi: not applicable
- templating: not applicable
- i18n: not applicable

### Rendering and deploy

- runsAs: always-on
- renderingModes: not applicable
- installMethod: RubyGems (gem install)

### License

- licenseModel: open-source
- license: GPL-2.0-or-later, Ruby (1.8)-specific terms

### Releases

- currentMajor: 6
- latestReleaseDate: 2021-12-25

### Adoption

- githubStargazers: unknown
- packagistDownloads: unknown
- npmWeeklyDownloads: unknown
- contributors: unknown
- pluginCount: unknown
- packagistMonthlyDownloads: unknown
- ecosystemsMonthlyDownloads: unknown
- httpArchiveSites: unknown
- wordpressActiveInstalls: unknown
- dependentRepos: unknown
- dependentPackages: unknown

### Sources

- name: https://yhbt.net/unicorn/README (read 2026-10-30)
- urls: https://yhbt.net/unicorn/README (read 2026-10-30)
- urls: https://yhbt.net/unicorn/README (read 2026-10-30)
- urls: https://yhbt.net/unicorn/README (read 2026-10-30)
- maintainer: https://yhbt.net/unicorn/LICENSE (read 2026-10-30)
- maintainerType: https://yhbt.net/unicorn/LICENSE (read 2026-10-30)
- category: https://yhbt.net/unicorn/README (read 2026-10-30)
- runtime: https://yhbt.net/unicorn/README (read 2026-10-30)
- runtimeMin: https://yhbt.net/unicorn/NEWS (read 2026-10-30)
- installMethod: https://yhbt.net/unicorn/README (read 2026-10-30)
- installMethod: https://yhbt.net/unicorn/README (read 2026-10-30)
- runsAs: https://yhbt.net/unicorn/README (read 2026-10-30)
- license: https://yhbt.net/unicorn/LICENSE (read 2026-10-30)
- license: https://yhbt.net/unicorn/README (read 2026-10-30)
- licenseModel: https://yhbt.net/unicorn/README (read 2026-10-30)
- currentMajor: https://yhbt.net/unicorn/NEWS (read 2026-10-30)
- latestReleaseDate: https://rubygems.org/api/v1/versions/unicorn.json (read 2026-10-30)
- firstRelease: https://yhbt.net/unicorn/NEWS (read 2026-10-30)

## Notes

Unicorn is an HTTP server for Rack applications. It runs as a long-lived process that spawns worker processes and reaps and restarts any that die. Its README describes the design as built for Rack, Unix and ease of debugging.

## Worth knowing

The README says the server is built for fast clients on low-latency connections, and that slow clients have to be served through a reverse proxy that buffers the request and the response. It also strongly discourages the use of Unicorn in new deployments, citing the damage the project has done to the Ruby ecosystem.

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Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attributes are recorded, never scored; absent means unknown.
Credit, in full: FindSoftware, CC BY 4.0