Add-ons for Mozilla Firefox and Thunderbird that I find invaluable.
Blocks annoying video ads on YouTube, Facebook ads, banners and much more.
Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
The easy way to download and convert Web videos from hundreds of YouTube-like sites.
This works also for audio and picture galleries.
The first and only download manager/accelerator built inside Firefox!
The best security you can get in a web browser!
Allow active content to run only from sites you trust, and protect yourself against XSS and Clickjacking attacks.
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Orkut, and many, many other sites. You can even customize Firefox and other programs themselves.
Restore squared tabs, appmenu, add-ons bar, small button view and more for Firefox 29+ (Windows/MacOSX/Linux).
All beta builds & changelogs can be found on versions page!
Tab Mix Plus enhances Firefox's tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager.
View and manage downloads from a tidy statusbar
This is a new life in Firefox 26+ for old well-known addon Download Statusbar
New Features: Replace Downloads Library page.
Now you have full control of your downloads history!
Screengrab! saves webpages as images.
New features: upload to internet
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.
Smooth dark theme for Thunderbird
• Firefox version available here
Collector's Note Thunderbird
HTML Validator is a Mozilla extension that adds HTML validation inside Firefox and Mozilla. The number of errors of a HTML page is seen on the form of an icon
For Firefox 23+, you need 0.958 (under review)
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