Adblock Plus is a content-filtering extension for web browsers which allows users to prevent page elements, such as advertisements, from being downloaded and displayed.
Adobe Flash Player
Adobe Flash Player lets users experience Web animation and entertainment in their Firefox, Mozilla, Opera, or Konqueror Web browser.
ArchView is an extension of Firefox, which can open archive file online without downloading the whole archive. ArchView supports RAR and ZIP formats; HTTP, FTP and file: protocols.
BiDi Browser UI
BiDi Browser UI is a simple extension for Mozilla and Mozilla Firefox, which allows Hebrew and Arabic users to control the direction of textareas and entire documents. It is also useful for users of other BiDi languages such as Urdu and Farsi.
Code bioFOX aims at implementing various bioinformatics tools as an extension on the Firefox browser.
Browser Bookmarks Menu
Browser Bookmarks Menu is a small Gnome applet to allow easy access to your browser's bookmarks, even when your browser is not open.
Browser3D is a Web browser that can interpret and display some non-standard HTML tags that are meant to describe 3D objects. Browser3D will ignore all normal XHTML tags and only display its own specific tags in a 3D environment. The tags can specify basic geometric figures such as planes, cubes, spheres, and cylinders.
Burster webbrowser 3D plugin
The Burster webbrowser 3D plugin uses the Blender Game Engine to integrate the fascinating world of 3D into a website.
CookiePie is a Firefox extension enabling you to maintain different cookies storage in different tabs and windows.
(commercial) lets you use many Windows plugins directly from your Linux browser. In particular CrossOver fully supports: QuickTime, ShockWave Director, Word Viewer, Excel Viewer and PowerPoint Viewer
Diggler is a small but powerful add-on for Firefox and Mozilla. It adds a menu button next to the address bar with actions relevant to the current URL, for example to step out to the parent directory, or to visit the equivalent ftp URL, or to visit the site in archive.org.
DisableBackspaceNavigation is a small extension for the Firefox web browser. The extension removes the back navigation function from the backspace key.
DjVu is a web-centric format and software platform for distributing documents and images. DjVu can advantageously replace PDF, PS, TIFF, JPEG, and GIF for distributing scanned documents, digital documents, or high-resolution pictures. DjVu content downloads faster, displays and renders faster, looks nicer on a screen, and consume less client resources than competing formats. DjVu images display instantly and can be smoothly zoomed and panned with no lengthy re-rendering.
DonkeyFire is a Mozilla Firefox extension. After configuring it, you will see a new element in the Firefox status bar, showing your download's progress.
Enigform is a Mozilla Firefox extension that provides you the ability to digitally sign an HTTP POST body generated from forms and AJAX .
Epilicious is an extension for the Gnome web browser Epiphany. It lets you synchronise your local bookmarks with the bookmarks in a Delicious account. It still quite rough around the edges, but fully usable.
exfm for Chrome and Firefox helps users get the most out of the exfm service. This browser extensions allows users to search for topics on popular sites such as Last.FM, SoundCloud or Bandcamp, and offers a new sensation in the field of streaming music. Read more
Fire.fm is a Firefox extension to access the extensive music library on Last.fm. It lets you listen to music related to your favorite artist and discover new artists and music in the process. It can also be used to listen to your friend's favorite music and to find Last.fm users with musical taste similar to your own.
FireBreath aims to be a cross-platform plugin architecture.
Fireflicks is a Firefox extension to upload and manage photos on flickr.com.
FireFTP is a free, secure, cross-platform FTP client for Mozilla Firefox which provides easy and intuitive access to FTP servers. Read more
Flash Plugin for Browsers
The Adobe (formerly Macromedia) Flash Player plugin for x86 Linux lets users experience Web animation and entertainment in their Mozilla, Firefox, Opera, or Konqueror web browser.
FlashGot is a free add-on for Firefox and Thunderbird, meant to handle single and massive ("all" and "selection") downloads with several external Download Managers. Read more
Fortify is a program that provides world-wide, unconditional, full strength 128-bit cryptography to users of Netscape Navigator (v3 and v4) and Communicator (v4). If you routinely use Netscape's export-grade web browsers, (i.e. the ones you can download from the Internet), then you need Fortify.
Gecko Media Player
Gecko Media Player is a browser plugin that uses GNOME MPlayer to play media in a browser. It should work with all browsers on Unix-ish systems(Linux, BSD, Solaris) and use the NS4 API (Mozilla, Firefox, Opera, etc.).
gHTTrack is a GNU/Linux frontend for Xavier Roche's HTTrack Website Copier for reading Web pages offline and/or for mirroring Web sites.
Hosaka provides the standard Unix text editing keyboard shortcuts for Google's Chrome browser input fields.
httpcmdd provides a way to have a (Web) browser user interface to programs running on the same machine as the browser.
HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility. It allows you to download a World Wide Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. HTTrack arranges the original site's relative link-structure. Simply open a page of the "mirrored" website in your browser, and you can browse the site from link to link, as if you were viewing it online.
IBM techexplorer is a plug-in for Netscape Navigator and Microsoft Internet Explorer, enabling the display of TeX, LaTeX, and MathML documents.
IEs4Linux is the simpler way to have Microsoft Internet Explorer running on Linux (or any OS running Wine). No clicks needed. No boring setup processes. No Wine complications. Just one easy script and you'll get three IE versions to test your Sites.
IGoogle Sidebar is a Firefox extension that displays your Google Personalized Home page in the sidebar. Only the modules on the left column of your Google homepage are visible in the sidebar, so you must select the ones you would like to see and drag them to the left column.
IntraLaunch is a Netscape plugin primarily designed for machines running X-Windows with Netscape that need to securely run programs from a web page. It allows HTML links to execute any kind of program or script.
KOffle is a KDE-tool for managing your wwwoffle spools (http and ftp) and your outgoing requests.
LeechCraft is a modular Internet client. It allows you to browse the Web; read RSS/Atom feeds; download files via BitTorrent, FTP, and HTTP; automatically download, play, or stream podcasts (and other media files); and much more.
Mailvelope is an open source browser extension for Google Chrome and Mozilla Firefox that allows the exchange of encrypted emails following the OpenPGP encryption standard. Mailvelope instantly secures your personal and professional email communications. Read more
Marvin is an extension to Google's Chrome browser that is designed to make life easier for reddit users.
Mobilizer is a catchy.net initiative to deliver a free, robust and full-featured WAP browser for Windows and Unix platforms.
The moji project aims to help foreigners learning Japanese language to read web pages. The main goal is to add lecture guides to chinese characters (kanji) and translations. It is a Mozilla Firefox & Thunderbird extension.
mozCC is an extension for Mozilla-based browsers, including Mozilla Firefox, Mozilla and Netscape, which provides a convenient way to examine Creative Commons licenses embedded in web pages.
MozGlade aims to provide a robust, flexible, scalable interface between libglade and the embedded Mozilla/GTK widget, and a user-program to leverage that interface.
Mozilla Quickstarter is a small kde utility that runs in the SystemTray and launchs the different programs of Mozilla (web browser, mail, chat, address book and composer).
mozilla-bonobo is a netscape-compatible browser plugin which allows your browser to use bonobo controls to display supported mime types.
MozPlugger is a modification of Plugger, a very small multimedia plugin for the Unix versions of Netscape, Mozilla, and Opera which uses external programs to show and play many file formats.
mplayerplug-in is a browser plugin that uses mplayer to play digital media from websites. This plug-in gives Mozilla the ability to play media from a website the net without reading the source html and getting the url manually. Media is played embedded in the page or in a separate window depending on how the author of the webpage intended the media to be seen.
myibay eBay bid sniper
This tool tracks and manage your eBay auctions privately and automatically bids in the last seconds on auction you choose
Mymail-Crypt for Gmail
Nautilus-audio-convert is a Gnome Nautilus?s extension that permits to convert audio files.