Extensions by Name
Skype Web Messenger brings Skype right into your browser to make audio and video calls.
Slashy Requires Restart
Fixes Windows backslash file separators in links and images and other types.
The Add-ons Manager slims down!
This add-on reduces the height of entries in the Add-on Manager, so you can display more of them at a time.
SM Home Button Requires Restart
Navigation bar Home Button (resurrected by sailfish)
SmartTemplate4 Requires Restart
SmartTemplate4 offers an easy way to automatically create customized replies by auto-inserting various mail headers. Templates can be created for every account as well as for the default (all email accounts). Also supports the Stationery Add-on.
smftn Requires Restart
download directly from QQ file transportation over 7/200 times limit
Smiley Fixer Requires Restart
Fixes Wingding Smileys in Outlook-generated emails
Smart Near-Infrared Control.
Soapy Requires Restart
Bypasses DNS-based censorship
NOTE: This was created as a SOPA protest in 2012. This does not work anymore for most sites. Use Tor instead.
SolusVM VPS Monitor Requires Restart
Status Monitor for SolusVM-backed VPS.
Sort and Search Customization Dialogs Requires Restart
Sort and search for buttons in (any) toolbar customization dialog
SourceEditor Requires Restart
View and Edit source of HTML element...
South African English spell checker Requires Restart
The South African English spell checker allows you to use place names, borrowed words, and other expressions that are unique to South Africa.
"No more eina, just a lekker spell checker!"
Spanish (Spain) ChatZilla Requires Restart
Spanish (es-ES) Language Pack for ChatZilla
Speed Dial Requires Restart
Direct access to your most visited websites
Speed Dial & Start Page with flexible layout for fast access to sites via visual bookmarks
SQL Cardfile Requires Restart
A simple card file database using SQLite as the backend.
SQLite Manager Requires Restart
Manage any SQLite database on your computer.
Use SeaMonkey as a standalone e-mail client. Set up a default browser for links opened from Mail & Newsgroups.
Stops autoplay of YouTube HTML5 videos (WebM). It is Flash-Block equivalent for HTML5 videos.