Using add-ons to troubleshoot, edit, and debug web projects .
Website Informer browser addon is a special tool to view essential statistics for any website during web surfing.
gPDF automatically sets links pointing to RTF, ODT, ODS, ODP, CSV files to open with Zoho Viewer; and links pointing to PDF, DOC, DOCX, XLS, XLSX, PPT & PPTX files to open with Google Docs.
A web discovery and search addon
Surf the web with this sidebar to find up to 300 websites similar to the one you land on.
Immediate access to 200 million sites reccomendations.
Empower your daily Google search session through the Getmore feature.
View Source In Dreamweaver is a new companion for web developers to open up any web page HTML source with Adobe Dreamweaver via a single and quick mouse click.
24 weekly downloads
The search engine for links using SEOmoz OSE. Enter a URL to start searching billions of URLs and trillions of links.
(Read very carefully: This Firefox Add-on is not built nor maintained by SEOmoz and they will not provide tech support for this)
15 weekly downloads
Metacrawler.de is online since 1998 and currently in the German-speaking countries, the metasearch engine with the second highest traffic (after MetaGer).
The Professor X Extension let's you see inside a page's head without viewing the sourcecode...