Latest additions that will be coming to Firefox 13 include performance improvements, new default tabs and improvements to the web developer tools.
Making Firefox “snappy” is a high priority for the Mozilla team. When loading tabs in a Firefox start-up, “only the active tab will load. Loading of background tabs is deferred until a tab is selected”, according to Lawrence Mandel on the Mozilla Hacks blog.
Mandel said that the “cycle collector is more efficient, spending less time examining memory that is still in use, which results in less pauses as you use Firefox”. Additionally, general performance improvements can be expected all-round Firefox.
A new “home tab” will be included. “Firefox will offer easy access to things users are familiar with today (Bookmarks, History, Settings, Downloads) as well as introduce the Apps Marketplace — a great place to discover exciting new content on the Web”, according to the Mozilla feature page.
As in the other modern web browsers, Firefox will include a “new tab” page. Currently, Firefox displays a blank page.
Mozilla is continuing with their improvements to the new web developer tools, as part of their 2012 desktop strategy they are including a “powerful and beautiful set of Web developer tools”.
Web developers will now have the ability to lock in a pseduo-classes such as :hover, making it easier to inspect the code. One of the most useful features will be the ability to edit CSS files in Firefox. Any changes will now be automatically saved if the CSS file stored locally (file://).
The expected release date is June 5 2012 and is currently available for download as a beta.

