Firefox 4 Announced by Mozilla, Release Coming in June
The upcoming release is a complete revision of browser, with a focus on increasing the speed of execution, adding support for HTML 5, along with a new interface. The development team stated that the release will be faster, feature different functions of the HTML 5 standard and will have a fresh user interface, along with stability and security.
Users of the browser will notice the new manager permissions which enable users to manage the data that sites have access to, and a new add-ons manager which enables browser extensions to be installed without a browser restart. New web development features include support for HTML5, CSS3, 3D and full-screen animation.