Mozilla is currently working on a new version of its open-source browser called Firefox 4.0. We have previously reported in the news that the beta version of Mozilla Firefox 4.0 should appear in June, and release the final version of the browser, obviously, will be held at the end of this year. Among the innovations the fourth version of Firefox, probably will go down the partial compatibility with Web standards, coupled with support for HTML5 and CSS3 multitouch functionality, as well as support of background updates, geolocation and features Firefox Sync.