The Differences between SeaMonkey versus Firefox and Thunderbird

Yes, I know. This page is way out of date.

The Mozilla open source project began as a way of developing the next generation of the Netscape Communicator suite. (See: The Relationship and History between Mozilla and Netscape) The Mozilla Application Suite, like Netscape Communicator, is an 'all in one' application, which contains a browser, email/newsgroups client, address book, and an HTML editor. Additional components, added to the suite were an IRC chat client, and web development tools (DOM Inspector, JavaScript Debugger).

A group of Mozilla contributors wanted to use the Mozilla code to build a much more streamlined product. They wanted to build just a browser, without the complications and added code, brought on by additional components. That product became Mozilla Firefox; and when the same thing was done to the email/newsgroups client, that product became Mozilla Thunderbird. There's even an equivalent product, for the HTML editor, called Nvu. (The IRC chat client, known as ChatZilla, is available as an extension.)

In the Spring of 2003, the Mozilla development roadmap was changed to focus development on the stand-alone applications Firefox and Thunderbird. Eventually, the Mozilla Foundation ceased development of the Mozilla Application Suite. Mozilla 1.7 was updated with security updates until April of 2006. (Version 1.7.13 was the last.)

A group of people in the Mozilla community, preferring Mozilla Suite's more in-depth interface, began a project called SeaMonkey, which aims to"deliver production-quality releases of code derived from the application formerly known as 'Mozilla Application Suite'." For instance, what would have been Mozilla 1.8 is SeaMonkey 1.0.

Inherent differences:

List of features/options the two setups do not share:

(F) - Indicates that an extension is available to add this functionality to Firefox.
(T) - Indicates that an extension is available to add this functionality to Thunderbird.
(S) - Indicates that an extension is available to add this functionality to SeaMonkey.

Firefox/Thunderbird SeaMonkey 1.1
Firefox 2
  • Automatic update system, including smaller update files
  • Extension Manager / Theme Manager
  • Built-in phishing protection
  • favicons are in bookmarks.html (hidden SeaMonkey setting)
  • customizable toolbars
  • Previewing and subscribing to Web feeds
  • search bar
  • Search term suggestions
  • Resume your browsing session after a system crash (S)
  • 'Go' menu remembers history between sessions
  • preferences are in Tools menu (Windows)
  • live bookmarks (S)
  • Live Titles
  • option to open a bookmark folder in a group of tabs (S)
  • Tabs can have a minumum width
  • Warning when opening many tabs at once
  • remembers page style [view -> page style]
  • History menu will keep a list of recently closed tabs (S)
  • Undo close tab (S)
  • Clear History, Saved Form info, Passwords, Download history, Cookies, and Cache, all with one button, or automatically. (S)
  • download manager can be purged on exit or successful download
  • 'clean up' button in download manager
  • disable plugin by file extension
  • update checks for extension updates too
Thunderbird 2
  • Automatic update system, including smaller update files
  • Extension Manager / Theme Manager
  • customizable toolbars(including a quote button)
  • preferences are in Tools menu (Windows)
  • RSS integration (S)
  • Session History Navigation
  • Folder Views
  • Offline Management automatically adjusts the offline state
  • Mail Notification Alerts show subject, sender, preview
  • Tooltip shows summary of the new messages, when mouse over a folder
  • Message icons indicate replied/forwarded status
  • links are opened in any browser (without having to have the SeaMonkey browser open)
  • Coloured quote borders(S)
  • Select Addresses window is embedded into the Compose window
  • Find As You Type in mailnews messages
  • Move / Copy again functionality
  • More versatile quicksearch
  • Roaming Profiles
  • Bookmarks button in Personal Toolbar
  • Notification when a bookmarked page is updated
  • Tooltip preview of tab's contents, when hovering on a tab
  • New tab created when dropping URLs and bookmarks between existing tabs
  • Print icon has dropdown menu (F)
  • "New Tab" button in the tab bar (available as a toolbar button in Firefox)(F)
  • sidebar
  • Password Manager, Image Manager, and Form Manager are accessible via the browser window menu bar
  • Override web sites that disable password autocomplete
  • Multi-line tooltips from web pages are displayed correctly(F)
  • Cookie Manager is accessible via the browser window menu bar(F)
  • block third party cookies
  • more keyboard shortcuts, particularly ctrl+I to get page info
  • quick launch(F)
  • dynamic profile switching
  • profile manager in start menu (also in Thunderbird, but not in Firefox)
  • profile manager creates a folder for new profile
  • location bar history and browser history are cleared separately(F)
  • 'Go' menu lists last 15 pages visited, whereas Firefox lists last 10.
  • history is displayed in independent window, with columns(F)
  • send page(F)
  • about:about, about:logo
  • A warning page before displaying about:config
  • edit page
  • Have context menu web searches open in a new page or new tab
  • upload files to FTP sites(F)
  • better and more complete text zoom
  • site navigation bar(F)
  • 'Open New Tab' can be set to automatically open your homepage(F)
  • Grippies(FT)
  • Plug-in support for mail and newsgroups
  • In Messenger, mail folders and newsgroups are accessible via the Go menu.
  • Ability to middle-click(or Ctrl+Click) on a link in mailnews, to open it in a new tab.
  • Ability to right-click on a link in mailnews, to open in a new tab or new window.
If you have found more items for this list, please contact me, so I can add them.