Firefox is regarded as the best Web browser in terms of extensions. It has hundreds of add-ons, which can be downloaded from here. But in this list I collected the most useful WordPress related Firefox extensions (addons). Let me know your own favorite add-ons in the comments.
Wappalyzer tracks the distrubition of software on the web and shows you which CMS, wiki, message board etc. is used on the page you’re currently at.
WordPress Helper 1.0.1
The Firefox extension WordPress Helper helps you working with WordPress by providing useful help and tools.
Deepest Sender is a client that will allow you to post to blogs from directly within Firefox. It is primarily a LiveJournal client, although it supports Blogger (GData) and WordPress (metaWeblog) too.
Screen grab to WordPress! 0.2
This addons ads to Screen Grab! by allowing screen captures to be uploaded to WordPress (2.5+) blogs via xml-rpc
MMD WordPress.com Extension 1.1
This extension adds a tiny statusbar panel that shows you your blog hit count for your WordPress.com blog
WordPress Post 0.17
This extension lets you post the text you select in your browser directly to your WordPress blog.
One-Click Installer for WP 1.1
Install plugins or themes on your self-hosted WordPress blogs with a single click (needs the related WP plugin to work; not intended for WordPress.com) .
Filling out Blog Comment Forms automatically with ease.