• Firefox 4 Beta 11 features the addition of support for the proposed "Do Not Track” (DNT) header – users can enable the DNT option via a check box under the "Advanced” tab in Firefox’s Preferences. Once enabled, a header will signal websites that support DNT that the user wishes to opt-out of online behavioural tracking. However, at this time, no web sites currently support the feature. The default homepage, the Firefox Start Page (about:home), has also had its design refreshed.

• "When the feature is enabled and users turn it on, web sites will be told by Firefox that a user would like to opt out of OBA,” Mozilla privacy lead Alex Fowler explained in a recent blog post. "We believe the header-based approach has the potential to be better for the web in the long run because it is a clearer and more universal opt-out mechanism than cookies or blacklists.”

• A small overlay is now used to show connection status messages and Firefox no longer switches into offline mode automatically. Additionally, support for WebGL, a royalty free specification that is essentially a JavaScript binding to OpenGL ES 2.0 (Open Graphics Library for Embedded Systems) that allows browsers to display hardware-accelerated 3D graphics without the need for a plug-in, has been re-enabled on Linux.

Source :- http://semanticseed.com/blog/?p=28349