There are many features for developers as well, including one that could be very important for users. Another change is better management of plug-ins. The browser integrates better visually with whatever operating system it is installed on by using OS-specific icons and toolbars, and taking on more of the operating system's look and feel. It also disables old, unsafe Firefox add-ins and extensions. Firefox now tells your antivirus software that it's downloading a file, so that your software can check it.

The newest version of Firefox includes other security features as well, including protection that warns you if you're visiting a site known to host or install viruses, spyware, Trojans or other malware. If a site has an Extended Validation SSL certificate, you'll be shown the owner of the site.

In addition, you can customize how you browse the site, setting features such as whether to allow pop-ups and cookies, and whether to load images. More useful is that you can click the 'More information' button that appears with the verification, and a tabbed dialog box pops up, allowing you to get a great deal of information about the site - whether you've visited the site before, whether it uses cookies, whether you have a password on the site and so on - and to view the cookies and passwords. However, some, such as PayPal, do, and hopefully more will in the future. As a practical matter, verification doesn't mean much right now very few sites use those certificates.

Click the favicon of the site you're visiting (located on the leftmost side of the address bar), and you'll be told whether it has been 'verified' as being the site it says it is, using its Extended Validation SSL certificate. There is a handy new security feature tied to the address bar. (In this beta, I found that the icon did not always show up on pages with RSS feeds.)

Similarly, when you're visiting a site on which there is an RSS feed, an RSS icon should show up, as it did in the previous version of Firefox. The list includes not just the site URL, but also the site name and favicon. As you type an address into the address bar, a drop-down list of sites you've visited and bookmarked appears. Also useful is a new search-as-you-type feature.

Firefox 45.0 beta 4 review