Having these addons installed can greatly enhance your web development or maintenance...
The Web Developer extension adds various web developer tools to the browser.
Note: If you are encountering the Connecting... problem see instructions below.
The updated, fully supported IE Tab. Embed IE in a Firefox tab. IE Tab Features: FF 4+ support, IE 7-9 compatibility modes, old IE Tab settings import.
This add-on provides the much needed feature update of Tab Duplication to Mozilla Browsers. Features Supported include Duplication of Browser Tabs, Detaching Tabs and Merging All Windows.
Provides close all blank/duplicate tabs and Close all tabs to the left/right plus many other options.