Export All Certificates Requires Restart
Adds an option to export all root certificates.
FLST (Firefox 4+) Requires Restart
Provides Focus Last Selected Tab and Tab flipping functionality (based on the FLST extensions by Gorgias and Gozer, but ported to Firefox 4/.../56 and repaired Tab flipping functionality). Enjoy!
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.
Block advertisement and access to adult sites
Switch tabs by scrolling with the mouse wheel in the tab bar.
A button to be able to open the profile folder, along with two buttons to create profiles, and also switch the current profile.
Makes every page to have light text on dark background (exact colors are customizable)
Firefox version is here: https://addons.mozilla.org/firefox/addon/dark-background-light-text/
KeePass Helper Requires Restart
Adds a hostname, URL, or email account ID to the application's window name (e.g., that of Firefox or Thunderbird) to make it recognizable to password manager utilities like KeePass.
Stylish Tools Requires Restart
Quicker access to several Stylish features through a toolbar button and/or keyboard shortcuts. Available for Firefox, Thunderbird, and SeaMonkey
Darkens the background of the page
Remember Mismatched Domains Requires Restart
The Remember Mismatched Domains extension for Firefox and Thunderbird adds a "Don't warn me again about this certificate for this domain" checkbox to the Domain Mismatch and Expired Certificate warning windows. When selected the domain...
This 15KB restartless add-on will add a "File" -> "Restart" menu item and a ctrl/cmd + alt + r hotkey to restart Firefox or Seamonkey.
InspectorWidget Requires Restart
Adds toolbar button and context menus for invoking the DOM Inspector (DOMi) for either chrome or content elements.
Adds buttons to toggle the using the default page colors and fonts, and the page defined colors and fonts.
Manage your installed personas (lightweight themes).
Password Tags Requires Restart
Adds metadata and sortable tags to the password manager.
ImageTweak: zoom/rotate images and videos! Requires Restart
A no-clutter image viewer for Firefox that allows you to zoom, rotate and display images/videos against a custom background. ImageTweak is a must-have addon for any photographer or photography-loving user.
Show all the menus in a single menu button that can be placed anywhere. Also contains replacement buttons for the default menus.
Sort and Search Customization Dialogs Requires Restart
Sort and search for buttons in (any) toolbar customization dialog
See more search results etc. on one page, concatenating several pages together...