Firefox is very popular among web developers because of its extensibility through various plug-ins and add-ons that were written by independent developers. The extension idea allowed solving a lot of various tasks directly in the browser without resorting to external tools.
Undoubtedly, you will find the familiar extensions in this list, but a lot of useful extensions always remain aside. So get ready to install a couple more extensions! :)
Built-in developer tools in Firefox
Fist we would like to mention the tools already built into Firefox. This article introduces a collection of development tools in Firefox Aurora 10 that could be found in any modern browser.
Mozilla has tried many approaches and solutions during the interface designing of these tools. Consequently, they got a nice interface that anyone can try by installing Firefox Aurora (Have you installed it yet?)
You will find below a big list of extensions, which is going to be useful for any web developer.