Mainly for my own records, but I’d be interested to see what other Firefox users consider to be their must-have extensions.
- Adblock Plus
- Ad killer – must-have.
- All-in-One Sidebar
- Opera-style sidebar control for access to sidebar panels.
- Firebug
- Excellent set of Web debugging utilities, integrating a javascript console, markup validation, document inspection and others.
- Fission
- Safari-style progress bar in address bar.
- Greasemonkey
- Manager and environment for client-side scripts. Usefl for fixing web annoyances or shoehorning extra functionality into third-party websites.
- Live HTTP Headers
- View HTTP headers of a page while loading. Essential for debugging protocol-level problems.
- Scrapbook
- Utility for saving webpages in the browser. Useful for saving flight confirmation pages and the like.
- Stop-or-Reload Button
- Combined Safari-style stop and reload buttons.
- View Cookies
- Add cookie pane to page info window.
- View Source Chart
- Renders document structure in a nested hierarchical view.