Firefox for desktops has become available for download. The main innovations are: support for the VP9 video codec, the Opus audio codec for WebM, multi-line flexbox and notifications from websites and web applications in OS X. A list of all changes in Firefox 28 under the cat.
Removed support for the SPDY 2 protocol (support for SPDY 3.1 has been added to Firefox 27 );
Implemented output of notifications about hanging of a background thread;
Added volume control for sound and video output via HTML5 audio and video tags;
Added support for mathvariant attribute from MathML 2.0;
Support for multiline CSS3 flexbox ( multi-line flexbox ) properties for simplified block layout of elements on the page.
Important
Firefox development with an interface optimized for Windows 8 Metro has been discontinued due to “lack of user interest. If millions of users take part in testing pre-release versions of Firefox for regular Windows, then the number of daily users participating in testing Firefox for Windows 8 Metro has not exceeded thousands. ”