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VKontakte.ru Downloader (music/videos/photos @ VK) Requires Restart

Download music, videos and photos from VK.com / vkontakte.ru. One-click download, natural filenames, displaying file size and bitrate for music, downloading HD video, downloading HQ photos. No spam, no usage of your account, no spyware.

Rated 4 out of 5 stars (504)
92,585 users

Image Zoom Requires Restart

Adds zoom and rotation functionality for images...

Rated 4 out of 5 stars (351)
88,799 users

µBlock

The most efficient blocker for Firefox.

No ads, no tracking, and insanely faster page loads.

Rated 4 out of 5 stars (243)
86,423 users

gContactSync Requires Restart

Synchronizes contacts & groups between Thunderbird or SeaMonkey and Google Contacts. Imports Facebook friends, contacts you follow on Twitter, and more.

Rated 4 out of 5 stars (226)
85,825 users

Remote XUL Manager

Manages the Remote XUL whitelist to allow websites and local files to load XUL content. For versions compatible with Firefox 41 and lower, see All Versions page below.

Rated 5 out of 5 stars (35)
81,042 users

Live HTTP Headers Requires Restart

View HTTP headers of a page and while browsing.

Rated 4 out of 5 stars (188)
79,046 users

UnMHT

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.

Rated 4 out of 5 stars (267)
78,264 users

JavaScript Debugger Requires Restart

As of Firefox 33, Venkman *no longer works*, as the APIs which it needs have been removed.

Venkman is the code name for Mozilla's JavaScript Debugger. Venkman aimed to provide a powerful JavaScript debugging environment for Mozilla based browsers.

Rated 4 out of 5 stars (50)
72,387 users

Saved Password Editor Requires Restart

Adds the ability to create and edit entries in the password manager.

Rated 5 out of 5 stars (331)
72,365 users

Youtube MP3 Podcaster Requires Restart

Self contained add-on for downloading youtube videos to mp3 for easy listening on podcasting gadgets like a Zune or iPod

Rated 4 out of 5 stars (252)
71,934 users

ChatZilla Requires Restart

A clean, easy to use and highly extensible Internet Relay Chat (IRC) client.

Rated 4 out of 5 stars (138)
69,739 users

DOM Inspector Requires Restart

DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.

Rated 5 out of 5 stars (75)
68,567 users

Proxy Tool Requires Restart

Proxy Tool - Powerful, yet User-friendly proxy tool to manage your proxies and anonymity needs, including: 46M+ user agents (world's largest), 10 different spoofed HTTP referrers, auto-proxy rotation, plus many more. Developed by http://ProxyList.co

Rated 3 out of 5 stars (45)
64,062 users

Thumbnail Zoom Plus Requires Restart

Shows full image when you hover over a thumbnail. Works with Amazon, Baidu Images, Bing Images, Facebook, Flickr, Google+, Google Images, IMDb, LinkedIn, Netflix, Pinterest, Reddit, Twitter, Yandex, YouTube, Wikipedia, Yahoo Images, & many more.

Rated 4 out of 5 stars (368)
63,626 users

Send Later Requires Restart

True "Send Later" functionality to schedule the time for sending an email.

Rated 5 out of 5 stars (105)
61,109 users

Bluhell Firewall

Get a faster browsing experience by blocking nasty web resources using Bluhell Firewall, the lightweight Ad-Blocker and Tracking/Privacy Protector.

Rated 4 out of 5 stars (481)
60,339 users

Mail Merge Requires Restart

Mass Mail and Personal Mail

Rated 5 out of 5 stars (150)
54,373 users

RefControl Requires Restart

Control what gets sent as the HTTP Referer on a per-site basis.

Rated 4 out of 5 stars (176)
51,469 users

DownThemAll! AntiContainer Requires Restart

Make the resources behind container pages easily downloadable by DownThemAll!

Rated 5 out of 5 stars (35)
51,426 users

HttpFox Requires Restart

An HTTP analyzer addon for Firefox

Rated 4 out of 5 stars (175)
48,738 users