F1 is a browser extension that allows you to share links in a fast and fun way. Share links from within the browser, from any webpage, using the same services you already know and love.

Use Gmail? Get Xoopit! Upgrade Gmail to search, browse & share files, photos & videos. Use Google Search while composing mail in Gmail. Get information about people in a Gmail conversation. Xoopit works for Gmail, Google Mail and Google Apps users.

The Minimap Addon gives you a suite of in-built maps and mapping tools for your web browser. Drag and Drop addresses or address links you find on web pages to view their location in the Map Sidebar, or by manually adding locations. Preview addresses from within any webpage using the Map Panel and get larger scale maps with the Map Tab.

Inquisitor for Firefox (Beta)... speeds up your searches like no other. Start typing and websites appear instantly, along with suggestions to help refine your search. Inquisitor understands you, learning and tailoring your results as you search more.

ClearForest Gnosis is the cutting edge of real time semantic processing for the web. By evaluating the pages you read – as you read them – Gnosis immediately locates key information such as people, organizations, companies, products and geographies hidden within the text.

autoHideStatusbar is a Firefox, SeaMonkey, Thunderbird and Flock extension that hides the status-bar.

Thunderbird extension Seek adds advanced search and sort functionality to the open source email client, Thunderbird, through a feature called faceted browsing. As you can see in the screencast above, faceted browsing narrows down emails by a number of conditions, introducing tons of useful ways to slice and dice your inbox to find exactly what you want.

The QuickText Thunderbird extension saves collections of reusable text snippets that help you whip up personalized replies to repetitive e-mail messages with a few keystrokes.

Attachment Reminder is a simple Add-on (extension) for Mozilla Thunderbird that scans your outgoing email when you click the send button and checks it for the presence of user-defined keywords that signal that an attachment should be included. If there is no attachment even though the scan indicates there should be, it will show a message box asking you to confirm whether you want to send the email without attachments.

Well, as people rely on email as a primary means of communication, and everyday users deal with a mounting level of new messages per day, even more advanced features can help all of us keep our inbox under control.

Enhances YouTube with Greasemonkey user scripts, that offer options like the FlowPlayer "doesn't start till you hit play" viewer, clean "theater" view, higher res videos, and links to download the video automatically.

Watch YouTube videos more efficiently with Better YouTube, a brand new Firefox extension that compiles our favorite YouTube Greasemonkey scripts into a single convenient package. Better YouTube smartly enlarges videos for better viewing, hides user commen

Operator leverages microformats and other semantic data that are already available on many web pages to provide new ways to interact with web services.

Extend Basecamp Project Management with this time saving firefox extension.

Post to Twitter from your Firefox address bar

Third-party extensions for the Epiphany browser (for Linux).

today we've got our top 10 list of unauthorized and unofficial but hella-useful apps that make Gmail that much better.

Links the Lightning Calendar extension for Mozilla Thunderbird to Google Calendar, enabling editing of your web calendar from your desktop.

Everyone's favorite photo-sharing web application, Flickr, has had tons of ancillary applications and user scripts developed for it to tweak, mod and add to its functionality. Dozens of Greasemonkey user scripts have popped up that make Flickr better; so

"To save you the time, I've compiled the best Greasemonkey scripts for Gmail into one handy Firefox extension, called Better Gmail."

"Javascript hackers have come up with some great Greasemonkey user scripts that make GCal easier to use, so I've compiled a few of my favorites into a single Firefox extension."

Thunderbird is the ultimate open source desktop email app. Its pluggable interface lets developers freely build extensions to make it ever more useful. And ever more useful do a few key extensions make it.

Google Browser Sync for Firefox is an extension that continuously synchronizes your browser settings – bookmarks, history, persistent cookies, saved passwords. It also allows you to restore open tabs and windows across different machines/sessions.

The Textarea Backup Greasemonkey script automatically saves text you've entered into a web page's textarea so that you don't need to worry about losing your latest online opus.