Mozilla has just come out with a new Firefox 21 open source browser release, just six weeks after its previous update, including at least eight security fixes, three of which were rated as being critical. In addition, the new browser comes with a range of new features including more social media integration and a new tool that ultimately wants to transform Firefox into the first ‘self-healing’ browser on the web.

A Healthier Browser?

The new Health Report feature is by far and away the most interesting new aspect of Firefox. Mozilla first mentioned that it was working on such a tool last year, saying it would incorporate a non-invasive reporting mechanism into its browser that would help it to keep track of its performance. As the name suggests, Health Report aims to deliver information to users about the state of their browser’s health, sharing that data with Mozilla so it can learn how to ‘cure’ problems whenever they arise.

In his blog post discussing the new feature, Mozilla’s Jonathan Nightingale reveals that Health Report will be automatically enabled by default in Firefox 21:

“As the health report uncovers patterns of problems in Firefox, we can build better support information for our users. In many cases, we will be able to detect these problems before they get out of hand, and your browser can start healing itself. The health report is enabled by default in Firefox but, if you don’t want your browser health information added to the pool, you can disable data sending either from the report itself, or from the Firefox preferences window.”

“Firefox Health Report gives us a powerful new tool. If you’re curious about what’s going on under the hood, you can find the health report in your Help menu. If you’re not, rest assured that we’re fascinated by this stuff, and we’ll use it to make Firefox the smoothest, fastest, most excellent way for you to live your life on the web.”

Also updated is Mozilla’s Do Not Track mechanism, giving users three choices: “Do Track,” “Do Not Track,” plus a new, third option that simply doesn’t tell websites anything at all, letting it work out for themselves what they want to do. According to Mozilla’s data, some 17% of users in the US choose to enable DNT at all times.

Better Performance

Mozilla is constantly pushing its browser for a better performance, and in the case of Firefox 21 no exception has been made. According to Nightingale, the new update incorporates new graphics subsystem changes that should lead to a better experience on both desktop and mobile versions of the browser.

Things are likely to get better too. Mozilla explained that its developers are still hard at work on the new OdinMonkey JavaScript engine that should make its way into a future version of Firefox. The aim of OdinMonkey is to be able to optimize the asm.js code and improve the performance of web-based games.

Social Enhancements

The desktop version of Firefox has also received an update to its social API, which allows sites to offer a sidebar that can pull in content from social media sites. Previously, this was only available for Facebook, but the service has now been updated to sites including the real-time trend tracker msnNOW, the Cliqz news service, and Japanese social media site Mixi. In addition, support has been added for Facebook Messenger.

Security Updates

Security-wise, Firefox 21 includes three critical security fixes that deal with memory-related flaws in the old version of the browser, plus another five fixes rated as non-critical. According to Mozilla, some of the vulnerabilities were discovered by researchers at Google using the open-source Address Sanitizer tool.

Updates to Firefox and Mozilla’s Thunderbird email client will be delivered via the automatic update feature in each application. For those who have disabled updates, it’ll be necessary download the new versions from the respective Firefox and Thunderbird download pages.