I have compiled a small list of Firefox plugins that come in handy.
First in the list come the plugins anyone might find handy; then, all the developer plugins.
I just love this one. Similar to Google Chrome’s default way of displaying downloads, except that way better. Lots of config options, too.
Bookmarks in the cloud. Cross browser. I love this one because it's really browser independant: the developers aren't related to any browser. Been using it for years and it just works, I really recommend it.
Search from the address bar... for any site. (Type "y", press space, search in youtube).
Similar to Google Chrome’s native support for Tab-searching.
Grab and Drag
Grab and scroll the page, the same way you do when reading PDF’s.
Menu Icons Plus
Just some eye-candy.
I guess I don't really have to explain this one, do I?
A ruler on screen. Comes in handy for web development.
Advanced eyedropper. Comes in handy for web development.
Take a screenshot of the web page. Upload it. All in one click. Also provides annotation and other image editing features.
A complete must. One of the best FTP tools out there.
Most popular tool for testing REST services.
Another tool for testing REST services. Relevant because Poster doesn’t save the settings, and you can always perform a GET by just navigating to the url.
Get nice formatted json. Navigate to http://search.twitter.com/search.json?q=Twitter%20API and see a mess? No longer.
I hope you found this list useful! I might edit it in the future, should I find any other significant plugins.
Thanks for reading! :)