Selective activation of plug-ins. Through "about: config" you can configure for each plugin the ability to process content using it only after explicit confirmation from the user. In particular, when this option is enabled for Flash plug-in, instead of Flash-content, a black area will be displayed with a suggestion to click the mouse to use the plug-in;
Improved site identification manager, which helps prevent SSL connections from being spoofed by using misleading favicon icons (a non-SSL website can issue a favicon icon in the form of a locked lock icon and the user might think that the connection is secure). From now on, favicon will not be displayed in the address bar, and instead they will show a service icon: a green closed lock - if the SSL certificate has passed the extended check, a gray closed lock - if the SSL certificate has not passed the extended check, the globe - is not used SSL or partially used SSL;
By default, all search queries to Google via the address bar or the quick access form to search engines are now made via a secure communication channel (HTTPS);
Full screen support for Mac OS X Lion;
The inclusion of default support for automatic addition of entered URLs as they are typed in the address bar of the Awesome Bar, without the need to select items in the drop-down list;
The implementation of the Pointer Lock API (Mouse Lock API), which allows game creators to get more control over the mouse, in particular to hide the regular mouse pointer and provide their own handling of mouse movement;
Implementing an API to notify the system of the inadmissibility of entering sleep mode, locking the screen, or starting the screen saver;
Support for pseudo-class state inspections has been added to the tools for web developers: when you hover the cursor on an element in the context menu of the inspection mode, various states are displayed, such as ": hover", ": active" and ": focus". If you select a state at the same time, it will be fixed in the process of further inspection;
Components of migration from Internet Explorer and Safari are rewritten to JavaScript;
In Linux, when selecting a dictionary, the $ LANG environment variable is now analyzed if it is impossible to determine the desired dictionary by another method;
Improved support for WebGL, resolved many problems. The browser is close to supporting the specification of WebGL 1.0.1;
Increased flexibility of the garbage collector, which can now be applied to an arbitrary set of “junction” (junction) JavaScript-objects, and not just all the compartments or one compartment, which will smooth the negative effect of pauses during garbage collection
The ability to restore the original state of the user profile if it is damaged or if there are performance or stability problems, without losing passwords, bookmarks, or browsing history (the “Reset Firefox” option in “about: support”);
Some less significant improvements for web developers;
Fixed 18 vulnerabilities, of which 9 were critical.