The two new features are support for the WebP image format and the AV1 video codec. Both are high-quality image and video compression technologies, respectively, that are expected to reduce bandwidth usage and improve page loading times.
Work on supporting these two standards started years back, but Mozilla only recently shipped AV1 and WebP spport after the two technologies gained some traction with other browser vendors, websites, and software makers.
In addition to these two new feature, Mozilla also improved two others that it added to Firefox in v63 and v64.
Enhanced Tracking Protection, also known as Content Blocking, which shipped with Firefox 63, has received a facelift of its settings panel, which now does a better job at explaining to users what they're blocking when enabling each of its three options.
Second, the new Task Manager-like about:performance page now shows the amount of RAM each Firefox page and extension is using, a feature it lacked when Mozilla launched it last month, with Firefox 64.
On the security front, Mozilla has also added protection against "stack smashing," a common security attack in which malicious actors try to create stack buffer overflows on purpose to take control of a vulnerable part of the browser's code.
According to Mozilla, stack smashing protection is currently being rolled out to macOS, Linux, and Android users only.
Also on the security front, Firefox 65's popup blocker also received an update to better prevent multiple pop-up windows from being opened by websites at the same time.
On the enterprise front, answering customer requests, Mozilla has also made available for the very first time 32-bit and 64-bit MSI installers for Firefox for Windows. Enterprise system administrators should now be able to trigger updates and new installations across a large number of machines using automated tools.
And last, but not least, starting with v65, Firefox will now warn users when closing a window, regardless if the user has automatic session restore enabled in the Firefox settings section.
For more details on today's changes, our readers can go to the Firefox 65 changelog here, the list of security fixes here, and the list of Web API and developer-related changes here.