IPFuck is a firefox addon created to simulate the use of a proxy. With this addon installed and enabled, and if a lot of us use it, there will no longer be any mean to know who is using a real IP, who isn't and who was charged doing something he didn't... Basicaly : we all become anonymous !

If you use the Internet Explorer, Google Chrome or Apple Safari browsers to conduct PayPal transactions, now would be a good time to switch over to the decidedly more secure Firefox alternative.

Les fonctionnaires du département d'Etat (Department of State, ou DoS), le ministère des Affaires étrangères américain, ont demandé à la secrétaire d'État, Hillary Clinton, de pouvoir utiliser Firefox.

The Firefox add-on China Channel offers internet user outside China to surf the web as if they were in China. Take an unforgetable virtual trip to China and experience the technical expertise of the Chinese Ministry of Information Industry (supported by western companies). It's open source, free and easy.

affiche le volume internet consommé dans la barre d’état en bas à droite

Remplacer les bannières publicitaires par de l'art !
Un ingénieux addon pour Firefox.

LanguageTool is an Open Source proof­reading soft­ware for English, French, German, Polish, and more than 20 other languages

It works with LibreOffice, Firefox, Chrome, or stand-alone.

TrackMeNot is a lightweight browser extension that helps protect web searchers from surveillance and data-profiling by search engines.

EDIT: maintenant intégré à Firefox

Greasemonkey is a Firefox extension that allows you to customize the way webpages look and function.

Hundreds of scripts are already available for free. And if you're the tinkerer sort, you can also write your own.

FireGPG is a Firefox extension under GPL which brings an interface to encrypt, decrypt, sign or verify the signature of text in any web page using GnuPG.

EDIT : le projet n'est plus maintenu. Utilisez https://www.mailvelope.com à la place!