It took us almost seven years to get from the first iteration of Firefox to version 4.0, but now we're already up to version 10, taking less than a year to get to double digits from the 4.0 launch thanks to Mozilla's new rapid release plan.
As well as a couple of little changes such as a hidden forward button, more compatibility with add-ons, extra WebGL and CSS3 support, the new browser also adds full screen APIs that allow you to build a web application that runs full screen. Basically, it's a load of developer changes rather than anything exciting on the front-end.
It seems like only weeks ago we were waxing lyrical about Firefox 9. Actually, it was - Mozilla seems to have Firebox on a six-week cycle. Google is just as crazy in hitting the high numbers with ubiquitous software releases though - in just over three years we're already up to version 16 (or 18 for the dev version).
The Android version of Firefox 10 adds multitouch gesture support to the mobile browser and, according to the Firefox 10 beta blog post, Firefox Sync will be "enhanced with an easier setup process so you can pair your Android phone, tablet or any Firefox-enabled device without needing to be at your desktop computer."
Super stuff. You can grab it now - it's free.