May 15, 2013, 6:54 AM — Mozilla on Tuesday released Firefox 21, adding more social media connections, tweaking the Do Not Track privacy setting and rolling out a new tool that long term, aims to create a self-healing browser.
The open-source developer also patched 15 vulnerabilities in the upgrade. Nine of those were rated "critical" by the company's security team.
Mozilla highlighted the new social media connections now built into Firefox in a blog post. The company debuted its Social API (application programming interface) last November with Firefox 17, which added a sidebar to show Facebook chat sessions and updates, including new comments, in the browser.
Firefox 21 now also supports the Cliqz, Mixi and msnNOW services with similar sidebars. Cliqz is a German-based news aggregator which already offers iOS and Android apps; Mixi is a Japanese social media network with an estimated 22 million users; and msnNOW is a Microsoft-owned news aggregator that claims approximately 13 million unique visitors monthly.
Although the developer preview of Firefox -- dubbed "Nightly" to note how often they're updated -- has also used the Social API to support the Chinese micro-blogging service Weibo since early April, Weibo did not make the final cut for Firefox 21.
According to a Mozilla spokeswoman, Weibo remains in testing.
Also new to the browser is a minor modification to the Do Not Track (DNT) privacy setting that expanded the choices to a trio. Where previously Firefox offered options that told compliant websites whether the user wanted to be tracked for advertising purposes, a third has been added that states, "Do not tell sites anything about my tracking preferences."
The third option is the new default setting for Firefox.
Mozilla also added a feature called "Firefox Health Report" (FHR) to the browser. FHR collects information -- speed of startup, number of crashes, number of add-ons and plug-ins -- and then displays the data to give users a better understanding of Firefox's performance, and provide tools to solve problems.
FHR is in its early stages, Mozilla cautioned, but it has plans for the tool, including using the reported data -- by default, the statistics are automatically sent to Mozilla -- to craft support documents.