Add-ons

FlashGot Mass Downloader by Giorgio Maone

Download all the links, movies and audio clips of a page at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers.

Session Manager by Michael Kraft

Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.

UnMHT by arai_a

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.

Collector's Note Support for mht format, one of IE's strengths.

Mozilla Archive Format, with MHT and Faithful Save by Christopher Ottley, Paolo Amadini

— Open web pages saved with Internet Explorer or other browsers (MHT)
— Save many tabs, video and audio reliably, in a single ZIP file (MAFF)
— Return to the original site you saved a page from, and more!

Thumbnail Zoom Plus by David Adler

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.

Save Images by Lumox

Save Images saves the images from the current tab page, from the cache, to a specified location, with either the images original file name or a file name that you specify.

Linkification by y5

Converts text links into genuine, clickable links...

Toolbar Buttons by Button Guy

Adds toolbar buttons to the customize toolbar window in several programs including Firefox, Thunderbird and SeaMonkey. Some of the buttons make commonly preformed actions quicker, others add new functionality.

QuickDrag by Stevie Smith

Extends the function of the drag-and-drop mouse gesture so that it can be used to load URLs, do a web search of selected text on a page, or save an image on a page. The successor to Super DragAndGo.

Collector's Note The best drag extension

CustomizeGoogle by CustomizeGoogle

CustomizeGoogle enhances Google by adding information and removing unwanted information.

Collector's Note Don't google without this.

Gmail Manager by Todd Long

The original Gmail notifier for multiple accounts. Allows you to receive new mail notifications along with viewing account details including unread messages, saved drafts, spam messages, labels with new mail, space used, and new mail snippets.

MR Tech Toolkit by mrtech

(Formerly Local Install) The primary goal of this extension is to provide the tools needed to install and manage extensions and themes locally and tons of other features.

Note: With Toolkit 6.0 Auto Archiving is fully working in Firefox 2.0 and temp...

Collector's Note another essential for Firefox

Update Notifier by Todd Long

Note from Mozilla: This add-on has been discontinued. Try Add-on Update Checker instead.

Notifies you when updates are available for your extensions and themes.

Single Key Tab Switch by oyvindio

Single Key Tab Switch provides configurable single hotkeys for switching tabs, like the 'Single-key shortcuts' feature of the Opera browser.

File Title by JasnaPaka

With this extension you can save HTML pages like in Microsoft Internet Explorer. Default filename is generated according to HTML tag TITLE.

Collector's Note Get one of the things IE does right - saving html page titles