Дополнения

always ".com" - Google.com (in English) от portuguesemike

Tired of being redirected to a local Google site when you specifically want Google.com?

Use "Google dot com", not "dot something else". Use Google.com, in English, without being redirected to a country-specific Google site when you're not in the US.

TryAgain от Paul Lammertsma, Mathijs

TryAgain keeps trying to load a webpage when the server cannot be reached.

FxIF от Christian Eyrich, Ted Mielczarek

View EXIF data in image properties

Restartless Restart от Erik Vold

This 15KB restartless add-on will add a "File" -> "Restart" menu item and a ctrl/cmd + alt + r hotkey to restart Firefox or Seamonkey.

Re-Pagination от Nils Maier

See more search results etc. on one page, concatenating several pages together...

Whois & Flags Firefox & Websites Popularity Rating от myip.ms

Display Country Flag indicating Website Physical Location (Country, State, City). Website Popularity (Live Visitor Statistics). Shows how many users are visiting any World Website per day. Website IP IPv6 Addresses, DNS, Hosting. IP Whois Lookup

Примечание подборщика Heavy whois + flag

IPvFox от Dagger

List the hosts, and corresponding network addresses, from which a page and its resources are loaded.

WikiLook от TestPilot, Rasha

Определение понятий с помощью Википедии и Викисловаря, без необходимости открытия нового окна или таба. На базе открытого кода.

Только версия 2.0.0 или более поздняя поддерживает русский язык.
Shift либо Ctrl либо Alt + нажатие правой клавиши мыши.

Примечание подборщика Great time-saver.