Web and Developer Tools
Live HTTP Headers Requires Restart
View HTTP headers of a page and while browsing.
RefControl Requires Restart
Control what gets sent as the HTTP Referer on a per-site basis.
MR Tech Toolkit Requires Restart
(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...
Scriptish Requires Restart
The greatest user script engine on the Internet (a fork of Greasemonkey).
jQuery Requires Restart
jQuery and jQuery UI embedded in browser
Dafizilla Table2Clipboard Requires Restart
Mozilla applications allow to select rows and columns from a table simply pressing Control key and picking rows/columns with left mouse button.
The selection can be copied to clipboard but the original table disposition is lost making ugly results wh...
Manages the Remote XUL whitelist to allow websites and local files to load XUL content. For versions compatible with Firefox 41 and lower, see All Versions page below.
IE Tab + (FF 8+, 7, 6, 5, 4, 3.6, 3.5, SeaMonkey) Requires Restart
IE Tab + is an enhanced version of IE Tab. It supports FF 3.5 or greater, integrates IE Tab with Adblock Plus in the IE Tab engine, and synchronizes cookies between IE and Firefox. You can easily import settings from the original IE Tab into IE Tab +
Link Properties Plus Requires Restart
Provides extended link properties: size of linked file, last modified time, etc.
As of Firefox 33, Venkman *no longer works*, as the APIs which it needs have been removed.
PrefBar Requires Restart
Restores version numbers for all installed add-ons inside Add-on Manager on Firefox, Thunderbird and Seamonkey.
Firesizer Requires Restart
Allows you to resize the window to specific dimensions.
NOTE: Users of Firefox 29 and above must install "The Addon Bar" extension to use this, as Firesizer uses the add-on bar that has been removed in Firefox 29.
Starts the remote debugger server.
Stylish-Custom Requires Restart
custom additions to Stylish extension
MR Tech Disable XPI Install Delay Requires Restart
Disables default delay when installing...
Automatically installs a set of domains to the Remote XUL whitelist.
MR Tech About:About Requires Restart
Adds the following "about:" options to the Help menu
Key Manager Requires Restart
KeyManager Tool: Firefox Add-on for Key Generation, Certificate Enrollment, CRL Signing, and Identity and Authority Delegation
View Source Requires Restart
Shows all source files of a webpage.