Firefox 21 now available, launches officially tomorrow
Firefox 21 is due to officially launch on Tuesday, but you can grab the desktop version now from Mozilla’s servers here: FTP.
If you prefer to wait for the official launch, keep your browser pointed to Firefox.com. Soon after it arrives tomorrow, Mozilla will also push it out via the browser’s automatic updates.
There’s no official Firefox 21 changelog as of yet, but the beta release notes should serve as a decent guideline (remember that features are sometimes added or removed before the stable version is released):