The latest pre-release of Firefox 6, Aurora 6, brings back support for WebSockets. WebSockets is a protocol for providing two-way communications between the browser and the server. Mozilla dropped support for WebSockets last year due to security issues.

Other notable features in Aurora 6 include the progress element, window.matchMedia API, better APIs for binary data and Server-Sent Events. You can download it here.

A look at the progress element element.

Here's a quick overview:

  • Progress element: As seen above, this element can be used for displaying progress bars.
  • matchMedia: The JavaScript equivalent of CSS Media Queries.
  • Server Sent Events: A way for a server side script to generate client side events which include data.

There are several other changes. You can find more information about the new features on the Mozilla blog. Some information about user interface changes can be found here.

Instead of bringing WebSockets into the mainstream browser, Microsoft offers plugins for developers who want to test unfinished specs.