Version History of Mozilla Firefox 4.0 (Beta 1)

  • Tabs are now on top by default on Windows only - OSX and Linux will be changing when the theme has been modified to support the change.
  • On Windows Vista and Windows 7 the menu bar has been replaced with the Firefox button.
  • You can search for and switch to already open tabs in the Smart Location Bar
  • New Addons Manager and extension management API (UI will be changed before final release)
  • Significant API improvements are available for JS-ctypes, a foreign function interface for extensions.
  • The stop and reload buttons have been merged into a single button on Windows, Mac and Linux.
  • The Bookmarks Toolbar has been replaced with a Bookmarks Button by default (you can switch it back if you'd like).
  • Crash protection for Windows, Linux, and Mac when there is a crash in the Adobe Flash, Apple Quicktime or Microsoft Silverlight plugins.
  • CSS Transitions are partially supported.
  • Full WebGL support is included but disabled by default at this time.
  • Core Animation rendering model for plugins on Mac OS X. Plugins which also support this rendering model can now draw faster and more efficiently.
  • Native support for the HD HTML5 WebM video format.
  • An experimental Direct2D rendering backend is available on Windows, turned off by default.
  • Web developers can use Websockets for a low complexity, low latency, bidirectional communications API.
  • Web developers can update the URL field without reloading the page using HTML History APIs.
  • More responsive page rendering using lazy frame construction.
  • Link history lookup is done asynchronously to provide better responsiveness during pageload.
  • CSS :visited selectors have been changed to block websites from being able to check a user's browsing history.
  • New HTML5 parser.
  • Support for more HTML5 form controls.