Up & Coming Extensions
Header Tools Lite Requires Restart
Allows to modify the header and the source of messages
Image Zoom Requires Restart
Adds zoom and rotation functionality for images...
Join-NG Requires Restart
Join partial messages. Somewhat similar to MS Outlook Express "combine and decode".
Confirm-Address Requires Restart
Confirm E-mail address before sending mail
Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.
Menu Wizard Requires Restart
Customize menus : Helps removing, moving and renaming menus and menu items
Colorize important menu for ease of use! (use Style (CSS))
Change or disable any of used keyboard shortcuts
Support: Firefox, Thunderbird and SeaMonkey
Adds toolbar buttons to the customize toolbar window in several programs including Firefox, Thunderbird and SeaMonkey. Some of the buttons make commonly preformed actions quicker, others add new functionality.
Reinstates the extensions.checkCompatibility preference without respect to the current application version.
As of Firefox 33, Venkman *no longer works*, as the APIs which it needs have been removed.
FiltaQuilla Requires Restart
Adds many new mail filter actions - launch a file, suppress notification, remove star or tag, mark replied or unread, copy as "read", append text to subject.
ThunderBirthDay Requires Restart
Display birthdays from the Thunderbird addressbooks as events in Lightning.
Quote Colors Requires Restart
Quote Colors allows you to select text and background colors of different quote levels which are applied when reading or printing mail/news messages. Additionally, you can choose between graphical and traditional plain text quoting display mode.
Adds icons to buttons and/or menus.
SeaTab-X-2 Requires Restart
Adds Firefox-style tab closers into SeaMonkey.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
The first and only download manager/accelerator built inside Firefox!
FlashGot Mass Downloader Requires Restart Featured
Download all the links, movies and audio clips of a page at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers.
Flexible Identity Requires Restart
Selects an identity based on the recipients list when sending an email
ChatZilla ru-RU Requires Restart
Russian translation of ChatZilla
QuickDrag Requires Restart
Extends the function of the drag-and-drop mouse gesture so that it can be used to load URLs, do a web search of selected text on a page, or save an image on a page. The successor to Super DragAndGo.