Firefox extensions
The Best
- Firebug: edit CSS inline, view Ajax requests and responses, debug Javascript with breakpoints...
- Foxmarks Bookmark Synchronizers: keep your bookmarks synchronized across different computers
Useful
- Web Developer: “Populate Form Fields” to test your forms...
- UrlParams: Shows GET/POST parameters in the sidebar
- Customize Google: add Google Suggest to the search field, favicons to Google result pages
- del.icio.us Bookmarks: seamlessly integrates del.icio.us