Didn’t Firefox 12 was just released? No matter, the Mozilla team is already working in version 13 and the beta is already available for download. Firefox 13 beta only brings minor tweaks but don’t underestimate, because it should boost the speed loading web pages.
Take this as an example, starting v13, restarting the web browser will not automatically load the tabs you had open in the background. Users will now have SPDY (pronounced ‘speedy’) protocol enabled by default, which essentially makes browsing experience a lot faster, and finally this latest release comes with a new default home page with better access to bookmarks and history.
Download link
Source Firefox beta notes via TheVerge