Mozilla on Tuesday, January 26 launched Firefox 44 for Windows, Mac, Linux, and Android. Notable additions to the browser include push notifications, the removal of RC4 encryption, and new powerful developer tools, VentureBeat reports.

Firefox 44 for the desktop is available for download now on Firefox.com, and all existing users should be able to upgrade to it automatically. As always, the Android version is trickling out slowly on Google Play.

Mozilla doesn’t break out the exact numbers for Firefox, though the company does say “half a billion people around the world” use the browser. In other words, it’s a major platform that web developers target — even in a world increasingly dominated by mobile apps.

Before we dive into the desktop versus mobile breakdown, there is one change that affects all four platforms: The RC4 cipher is no longer supported over HTTPS connections. RC4 is a stream cipher designed in 1987 that has been widely supported across browsers and online services for the purposes of encryption. Multiple vulnerabilities have been discovered in RC4 over the years, making it possible to crack within days, or even hours.