LICENSEWARE
Mozilla Rule

Modified Mozilla software may not keep Mozilla trademarks without prior written permission

Catalog row in Vendor License Rules · Cited

Kind
Restriction
Statement
Distribution Policy for Mozilla Software (undated; as published on 2026-09-27): changes to Firefox or other Mozilla software, including a changed default home page or bookmarks, added extensions or plugins, changed installer content or file locations, may not be redistributed under any Mozilla trademark without prior written consent and, typically, a distribution agreement. A modified Firefox may not continue to be called Firefox. The Trademark Guidelines require forks to choose their own name and branding.
Applies when
Redistributing a modified build (changed defaults, bundled extensions, altered installer) under a Mozilla name.
Applies to
Customised, repackaged or rebuilt Firefox and Thunderbird distributed to others.
Esc