SeaMonkey browser

This page was last updated at: May 26, 2026

SeaMonkey is a Desktop web browser and supports the Linux, macOS, Windows operating systems. It is developed by SeaMonkey Council. It has been developed for about 21 years since launching in 2005.

SeaMonkey preserves the more traditional look and feel of Firefox, as well as still using the legacy XPCOM-based system to provide Add-on functionality.

SeaMonkey includes the browser, but also includes a Mail client and HTML editor; the code is based on Mozilla's original Mozilla Application Suite.

The release date and the latest version number of SeaMonkey is displayed on the download page - this is very useful - it means you can easily tell how recently the latest version has been released. Using versions of software that were released a long time ago is bad security practice; the software may have old, unpatched bugs in it. Version number is shown next to downloads and the news blog announces the dates.

About SeaMonkey

Browser URL www.seamonkey-project.org
Browser made by SeaMonkey Council
Development Status Active
Updates aren't very frequent, but the team does continue to develop SeaMonkey
Launched 2005
Operating Systems Linux, macOS, Windows
Device platform Desktop
Rendering Engine Gecko
NPAPI support SeaMonkey continued to support NPAPI plugins for a while after it was dropped from mainstream browsers, but it dropped support with Version 2.53.1, and it was completely removed in Version 2.53.7 (March 2021).
Formerly known as Iceape
Wikipedia Article https://en.wikipedia.org/wiki/SeaMonkey
Forum Post
2023-10-21
 Thoughts on using SeaMonkey as a light, fast and privacy oriented browser in 2023?
Most people in the thread don't think SeaMonkey is great...

SeaMonkey milestones

  1. Mozilla Foundation announces the end of Mozilla Application Suite
    Thus setting the stage for the creation of SeaMonkey's suite
  2. SeaMonkey's first release
  3. Official 1.0 release of SeaMonkey

Check out other browsers similar to SeaMonkey

These web browsers have something in common with SeaMonkey, you could test them out and compare them.