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SeaMonkeyFirefox ESR
Free

The software is free under its open-source licence. Hosting, hardware and external…

 Free

Free and open source; Mozilla offers optional paid professional support for organisations.

Windows, macOS, Linux Windows, macOS, Linux
  • It is the continuation of the old Mozilla Application Suite, so browsing, mail, news and page editing live…
  • Long-term stable feature set for managed deployments
  • MSI and PKG installers plus group policy templates
  • It tracks an older Firefox codebase, so web compatibility and security hardening trail the current browsers.
  • New features arrive later than in regular Firefox
  • Mainly aimed at organisations rather than home users
Downloadable app Downloadable app
Open source Open source
License: MPL-2.0 License: MPL-2.0
Not stated if an account is needed No account needed
Not stated if it works offline Not stated if it works offline

Checked September 22, 2026

Checked September 24, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.