Mozilla on Tuesday pushed Firefox 42 out on its public channel with plenty of noteworthy additions in tow. The biggest change of all, however, is the addition of a feature called Tracking Protection.

Designed to bolster Firefox’s existing Private Browsing mode, Tracking Protection is more or less an ad blocker. As Mozilla explains, most websites rely on many different third-parties to provide things like analytics, social network buttons and display advertising. Some third-parties use page elements to track browsing activity in order to build profiles about its users.

Private Browsing mode with Tracking Protection blocks some page elements that could be used to track user behavior across sites.

This means that advertisers that attempt to track users won’t get paid for impressions because their ads won’t be shown. As PCWorld explains, it’s not the end of the world for advertisers considering Firefox represents a small percentage of total browser users (fewer still use Private Browsing).

Something else the publication points out is the fact that because Google and Microsoft have advertising-based businesses, it wouldn’t be in their best interest to roll out similar features for their respective browsers.

Firefox 42 also brings an icon to tabs playing audio with the option to mute it with a single click. Firefox is playing catch-up here although the one-click mute function is a nice touch not yet seen elsewhere. There’s also an improved Control Center with site security and privacy controls as well as a revamped Login Manager sporting several improvements.

Firefox 42 is available as of writing for Windows, Mac OS X and Linux.