Most Popular Extensions
SeaTab-X-2 Requires Restart
Adds Firefox-style tab closers into SeaMonkey.
Quote Colors Requires Restart
Quote Colors allows you to select text and background colors of different quote levels which are applied when reading or printing mail/news messages. Additionally, you can choose between graphical and traditional plain text quoting display mode.
Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.
The first and only download manager/accelerator built inside Firefox!
Lightbird Requires Restart
Standalone calendar UI for Lightning
P7MON Requires Restart
Abilita la gestione alternativa degli allegati P7M
Extra Format Buttons Requires Restart
Adds a font size (in pixels), strikethough, subscript and superscript buttons to Thunderbird's Compose Window.
Image Zoom Requires Restart
Adds zoom and rotation functionality for images...
Saved Password Editor Requires Restart
Adds the ability to create and edit entries in the password manager.
Get a faster browsing experience by blocking nasty web resources using Bluhell Firewall, the lightweight Ad-Blocker and Tracking/Privacy Protector.
A fork of PDF.js with support for SeaMonkey 2.49.x.
ThunderBirthDay Requires Restart
Display birthdays from the Thunderbird addressbooks as events in Lightning.
FireFTP Requires Restart
FireFTP is a free, secure, cross-platform FTP/SFTP client for Waterfox which provides easy and intuitive access to FTP/SFTP servers.
Check out my new project, FireSSH!
Speed Dial & Start Page with flexible layout for fast access to sites via visual bookmarks
Flexible Identity Requires Restart
Selects an identity based on the recipients list when sending an email
Return Receipt Toolbar Button Requires Restart
Allow you to add a Return Receipt button to mail compose window toolbar.
GNOMErunner Options Requires Restart
Allows to customize GNOMErunner theme
Show contact photo and other info from Local Dir, Addressbook, LDAP, Facebook, LinkedIn, Flickr, Gravatar etc
Simple Locale Switcher Requires Restart
An easier management of the user interface language
This Addon simply adds a dropdown button that lets you download YouTube Videos in various Formats. Download YouTube Videos in FLV, 3GP, MP3, MP4, 720p, 1080p in a single click.