Lightning Requires Restart Featured
Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
Provider for Google Calendar Requires Restart
Allows bidirectional access to Google Calendar
gContactSync Requires Restart
Synchronizes contacts & groups between Thunderbird or SeaMonkey and Google Contacts. Imports Facebook friends, contacts you follow on Twitter, and more.
Send Later Requires Restart
True "Send Later" functionality to schedule the time for sending an email.
QuickNote Requires Restart
A simple note-taking extension.
Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.
UnMHT allows you to view MHT (MHTML) web archive format files, and save complete web pages, including text and graphics, into a single MHT file in Firefox/SeaMonkey.
Mail Redirect Requires Restart
Allow to redirect (a.k.a. "remail") mail messages to other recipients.
PlayFlash 32bit Requires Restart
Flash player plugin - unofficial xpi repack for 32bit browsers.
Use when official plugin installer is not suitable.
All binary files are copyrighted by their authors and distributed for free.
SmartTemplate4 Requires Restart
SmartTemplate4 offers an easy way to automatically create customized replies by auto-inserting various mail headers. Templates can be created for every account as well as for the default (all email accounts). Also supports the Stationery Add-on.
ChatZilla Requires Restart
A clean, easy to use and highly extensible Internet Relay Chat (IRC) client.
AutoProxy-ng Requires Restart
This is a fork of AutoProxy, which can run the latest version of Firefox.
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.
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.
AutoCopy 2 Requires Restart
Copies selected text to the clipboard automatically.
MinimizeToTray Requires Restart
Minimizes Mozilla windows into the system tray. Also includes a right clickable tray icon menu to further load only the windows you want visible...
PlayFlash 64bit Requires Restart
Flash player plugin - unofficial xpi repack for 64bit browsers. Use when official plugin installer is not suitable. All binary files are copyrighted by their authors and distributed for free.
Mouse Gestures Suite Requires Restart
Mouse gestures for SeaMonkey & Firefox: navigate & execute commands using mouse gestures (with single mouse button) and rocker gestures (by pressing 2 mouse buttons). Also: scroll wheel navigation, page scrolling, tab scrolling.
Highlighter Requires Restart
Quickly highlight some text in Thunderbird message composing windows.
Diagnostics tool for Adblock Plus, provides some insight into internal processes of Adblock Plus.