Firefox 9 Is Coming in Three Days, Here's What You Need to Know

Firefox 9 is almost here. Well, Firefox 9 is already here if you're brave enough to grab the release candidate builds that Mozilla has made available but hasn't announced officially. Whether you can or can't wait for three more days (Firefox 9 is coming on December 20) here's what to expect from the latest Mozilla release.

Type Inference

The most touted new feature is Type Inference in the JavaScript engine. It's a technical feature, the details of which interest more programmers than regular users.

The main takeaway is that Firefox should be able to run JavaScript-heavy websites, meaning pretty much everything these days from Gmail to Twitter, faster.

Type Inference is a technique through which languages like JavaScript, which don't declare variable types from the get go, can eliminate some of the overhead that comes with determining type at runtime, leading to a performance boost.

There's a slightly more detailed explanation of how and why Mozilla implemented type inference in Firefox over here.

'Do Not Track' checking via JavaScript

Another addition in Firefox 9 is a method for checking for the "Do Not Track" option via JavaScript, rather than just reading the HTTP header.

This should make it easier for apps and websites to check for the privacy option and take the appropriate measures.

Do Not Track is a method introduced and implemented by Mozilla to enable websites to determine whether users agree to having their browsing tracked, for targeted advertising, or not.

Improved support and integration for Mac OS X Lion

Firefox 9 also integrates better with the latest Mac OS X. It does a better job at blending in with the native look and feel thanks to an improved theme integration. There is also support for two finger swipe navigation.

New Tablet UI

The mobile version of Firefox 9 comes with a brand new and customized interface for Android tablets. It's been in the works for the past few months and it's now ready for the prime-time.

Under-the-hood improvements

Of course, a lot of work has been put into improving Firefox in places where users won't notice directly. Firefox 9 comes with better support for the HTML5, MathML and CSS standards.

There is also support for the font-stretch CSS property, which you can guess what it does from the name. It is also possible for websites to tell Firefox how to handle overflowing text, another CSS property that is now supported.

Firefox 9 is coming in three days and if you're using Firefox 8, you should be getting an updated in the next few days after that.