SeaTab-X-2 Requires Restart
Adds Firefox-style tab closers into SeaMonkey.
QuickFolders (Tabbed Folders) Requires Restart
The "Swiss army knife" of folders. Turn your favorites into tabs - open folders and subfolders, move mails without scrolling around or searching. powerful + easy.
See new mail at a glance after automatic filtering - supports quickFilters addon!
IMAP Received Date Requires Restart
Make the “Received” column in IMAP folders show when messages were actually received.
'Classic Toolbar Buttons' add-on restores old toolbar button ui (known from Fx 4-7 small view, Fx4-12 large view & Tb5-14) for current Firefox, Thunderbird and Seamonkey versions.
HTitle (discontinued) Requires Restart
Hide title bar if window is maximized.
This add-on has been discontinued!
Legacy extensions support will be dropped in Firefox 57. If you interest in CSD on Linux, please track progress on https://bugzilla.mozilla.org/show_bug.cgi?id=1283299.
Restrict Proxy by Private Windows, Tabs and Domain List
Webmaster SAPE Requires Restart
Toolbar contains a set of functions, which expands the abilities of webmasters and optimizers, when working in the interface of SAPE exchange.
Restores the default image style used for top-level images in previous versions of Firefox.
Adds private tabs.
If you are the kind of person who likes to have total control over every aspect of your downloads, "Download Status Bar" is the add-on you are looking for.
Restores version numbers for all installed add-ons inside Add-on Manager on Firefox, Thunderbird and Seamonkey.
No Message Pane Sort by Mouse Requires Restart
No Message Pane Sort prevents accidental resorting of the message pane by disabling mouse button clicks on the column headers.
It is still possible to sort messages by ctrl-clicking the header.
Right Links Requires Restart
This extension allows to open links in new tabs with right-click directly and using “long” left-click.
This is very useful for touchpads on notebooks and for mice without middle button.
Saved Password Editor Requires Restart
Adds the ability to create and edit entries in the password manager.
F.B. Purity hides the ads, app spam and other annoying clutter from your facebook news feed, lets you increase the font size, change colours plus many more features and generally makes Facebook a lot less annoying to use.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
Speed Dial & Start Page with flexible layout for fast access to sites via visual bookmarks
Send Later Requires Restart
True "Send Later" functionality to schedule the time for sending an email.
Search in the address bar without changing your search engine.
Sun Cult Requires Restart
Worldwide Sunrise, Sunset, Twilight, Moonrise and Moonset...