Do Not Track fine-tuning in Firefox 21

A more granular approach to how Firefox has implemented the controversial "Do Not Track" setting leads off the changes to Firefox 21, which updated on Tuesday. Also in the browser is support for more social networks including MSN Now and a "Firefox Health Report."

More options for the Social API, which debuted at the end of last year with Facebook Messenger integration, allows Firefox 21 (download for Windows | Mac | Linux) to work with MSN Now, Cliqz, China's Weibo, and the Japan-only Mixi. While there's no doubt that they're not even on a scale to compete with Facebook, they still command millions of combined users. Wikipedia's Weibo page said that the service alone had 368 million users as of mid-2012.

Mozilla has lofty goals for the Social API that strech beyond just social networks. "The Social API has endless potential for integrating social networks, e-mail, finance, music, cloud possibilities, services, to-do lists, sports, news and other applications into your Firefox experience," the company wrote on its blog announcing the update.

As with the Facebook integration, which was restricted to little more than Messenger, Mozilla has focused the Social API on delivering limited features of a social network, as opposed to all the features a social site offers. Mixi integration connects its Japanese-speaking Firefox users with their comment and photo streams. Mozilla has yet to summarize which aspects of Weibo are supported in the Social API sidebar.

The MSN Now integration (sign-in) brings trends collected from Facebook, Twitter, Bing, and BreakingNews.com to its Social API sidebar. Cliqz integration (sign-in) appears similar and creates a personalized news stream that follows people as well as stories and trends, and allows you to save stories to read later.

Do Not Track has remained unchanged since it debuted in 2011's Firefox 4. It sends a signal to Web sites that the visitor should not be followed as they explore your site or move on to different ones. Abiding by that signal is completely voluntary. Sid Stamm, Firefox's privacy lead engineer, wrote that the Do Not Track goal is "to help each individual say what they want, whether it's pro-tracking or not."

"When DNT is off, it doesn't mean 'please track me.' It means that the user hasn't told the browser their choice yet," wrote Tom Lowenthal, another security engineer at Firefox. When you install Firefox for the first time, he said, the browser is set to neither so that the choice is entirely the user's.

However, it's hard to imagine "no signal" having an effect on aggressive advertisers and tracking cookies that's any different from a "track me" signal in the header. More useful in protecting people is likely to be Firefox's new feature to aggressively block tracking cookies, which is expected in July when the next version of Firefox arrives.

Also in the new Firefox 21 is the Firefox Health Report, which offers advice on how to better customize Firefox to minimize its impact on system performance.

Firefox 21 for Android (download) appears to have the same new features as its beta predecessor. It offers new default fonts, the open source Open Sans and Charis fonts to replace the default Android fonts in the Web browser. Mozilla changed the Firefox for Android fonts to "enable a more visually appealing and clear reading experience on the Web," the company wrote in its blog post about the Firefox for Android updates.

Full release notes are available for Firefox for desktops and Firefox for Android.