Track Package Requires Restart

Track Packages from the right-click menu...

Flat Folder Tree Requires Restart

Selectively breakout or promote sub-folders under an intermediate folder in the folder tree. Use with IMAP servers where some folders remain collapsed under special namespace like [Gmail] or the INBOX itself.

Korean spellchecker

Korean (ko-KR) spellchecker

No More Install Delay

UPDATE: XPI delay has been removed in Firefox 40!

Disable the install delay in Firefox. New 2.0 version now includes GreaseMonkey scripts!

Unlike similar addons, this works on Firefox 4 and beyond.

Free Memory Button

Free unused memory that Firefox is currently using.

Slovak spell checking dictionary

Slovak spell checking dictionary for Mozilla applications (based on the "open-source" dictionaries by Zdenko Podobný).

Restart application Requires Restart

Restart the application with one click (or Ctrl Shift Z)

Page Colors & Fonts Buttons

Adds buttons to toggle the using the default page colors and fonts, and the page defined colors and fonts.

Sender Name Requires Restart

Lightweight Themes Manager

Manage your installed personas (lightweight themes).

DragToCompose Requires Restart

Enables dragging a file to Thunderbird for composing a new message without opening composer window first.

Show Password On Input Requires Restart

Gives an option to show the master password on input

Urdu Dictionary

This dictionary is based on the urdu word list provided at www.crulp.org and the word list compiled by our friends at http://www.urduweb.org/mehfil/

AddressLabel Requires Restart

Create address labels from selected contacts in pdf, odt, ps or html.

Usage
1) Chose settings.
2) In the Address Book, select contacts and right click.
3) Print with "Actual Size" (not "Fit to Page").

All Menus Button

Show all the menus in a single menu button that can be placed anywhere. Also contains replacement buttons for the default menus.

ThunderTabs Requires Restart

This add-on is a button on your toolbar that lets you open web apps as Tabs in Thunderbird. Use it to load Google Mail, Google Wave, Google Voice, and other "inboxes" (or any url) as tabs within Thunderbird, making it your communications hub.

English-Russian dictionary

Spelling of English and Russian words

Restart App Button

Restart the current application, as you might need to do after installing a new extension or theme.

FromToGMAP Requires Restart

Calculation of the distance and delay between reference address and highlighted address with the Google Map engine. Right click with mouse, select 'Distance with FromToGMAP' and the calculation of distance and delay appear in a popup

Search IP Requires Restart

This plugin adds three links to Firefox's context menu that lookup the selected IP address at Project Honey Pot, Utrace, spamhaus, senderbase,...