# Boulder

ACME-based certificate authority written in Go, the software that runs Let's Encrypt.

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/boulder/
Last reviewed: 2026-10-28
Listed since: 2026-10-28

## Record

### Links

- repository: https://github.com/letsencrypt/boulder

### Identity

- status: stub
- maintainer: Internet Security Research Group
- maintainerType: unknown
- parent: unknown
- firstRelease: 2022
- hqCountry: unknown

### Kind

- category: web-server
- hosting: unknown
- language: go
- runtime: unknown
- runtimeMin: unknown
- 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: unknown
- renderingModes: not applicable
- installMethod: unknown

### License

- licenseModel: open-source
- license: MPL-2.0

### Releases

- currentMajor: unknown
- latestReleaseDate: 2026-10-27

### Adoption

- githubStargazers: 5776
- packagistDownloads: not applicable
- npmWeeklyDownloads: not applicable
- contributors: 133
- pluginCount: unknown
- packagistMonthlyDownloads: unknown
- ecosystemsMonthlyDownloads: unknown
- httpArchiveSites: unknown
- wordpressActiveInstalls: unknown
- dependentRepos: unknown
- dependentPackages: unknown

### Sources

- urls: https://api.github.com/repos/letsencrypt/boulder (read 2026-10-28)
- maintainer: https://letsencrypt.org/about/ (read 2026-10-28)
- category: https://github.com/letsencrypt/boulder/blob/main/README.md (read 2026-10-28)
- language: https://api.github.com/repos/letsencrypt/boulder (read 2026-10-28)
- license: https://github.com/letsencrypt/boulder/blob/main/README.md (read 2026-10-28)
- licenseModel: https://github.com/letsencrypt/boulder/blob/main/README.md (read 2026-10-28)
- firstRelease: https://api.github.com/repos/letsencrypt/boulder/releases (read 2026-10-28)
- latestReleaseDate: https://api.github.com/repos/letsencrypt/boulder/releases (read 2026-10-28)
- githubStargazers: https://api.github.com/repos/letsencrypt/boulder (read 2026-10-28)
- contributors: https://api.github.com/repos/letsencrypt/boulder/contributors?per_page=1 (read 2026-10-28)

## Notes

Boulder is an ACME-based certificate authority, written in Go. Its README says it is the software that runs Let's Encrypt, and that it verifies an applicant controls an identifier before it issues a certificate.

The README also says the software is intended only to support the Web PKI, that the Docker development environment is not suitable for production use, and that organizations evaluating it for production should look at another project.

## Worth knowing

The README describes the software's use for its operator and does not describe a use for site owners, so the record is a stub. The project has no homepage of its own; the service it runs is provided from letsencrypt.org.

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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