So you’re one of the 8 million people who downloaded Firefox 3 yesterday. What next? Here are some links to get you started..
Uses PDFKit to display PDFs in the browser.
firefox-mac-pdf
Lifehacker - Power User’s Guide to Firefox 3
MultiFirefox 2.0 | Code Contortionist
Run Firefox 2.0 alongside Firefox 3.0 for webdev testing purposes.
Firebug
Firebug integrates with Firefox to put [...]

In computing, an integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of a source code editor, a compiler and/or interpreter, build automation tools, and (usually) a debugger.
Having used various IDE (JCreator, Eclipse & Microsoft Visual Studio) during the course of learning [...]