For those of you working in Apple's Mac OS X Lion environment, you'll now have improved theme integration in-browser. You'll also have the ability to two-finger swipe inside windows if you're using Lion, a feature that until now was only available in a stable form inside Safari. You've now got improved support for text-overflow and a brand new support for font-stretch.
Stability issues have been taken care of in several hush-hush ways, and you'll be able to download this new version for Windows, Mac, or Linux, provided your version of any of these is the most recent or nearly the most recent version. You can do so through the Future of Firefox page for downloads and grab all the notes and details on this release on the Firefox 9.0 Release Notes page at Mozilla. On the other hand if completely stable versions of software are more your level of experience, you can still go back to the Firefox latest releases downloads page and hit your icon!