A new Firefox Beta for Windows, Mac and Linux is now available for download and testing. The biggest addition in this update is significant JavaScript improvements, courtesy of Mozilla’s new JavaScript JIT compiler called IonMonkey. The new beta features JavaScript improvements to make web apps and games perform better, while also adding support for W3C Touch Events. One of its headlining features is the Retina Display support that the beta brings to Mac users. IonMonkey has been a long time coming with the primary aim of enabling new optimizations that are impossible with the current architecture.

Firefox users on all platforms will happy to learn about the addition of the built in PDF viewer, while Mac users will be pleased to note that the Firefox beta also adds supports Retina Display. Developers mean while will want to know that the new version supports standard W3C touch events in addition to Moztouch events. Firefox other features include early WebRTC support, performance improvements, CSS3 Flexbox support, and much more. Today we enabled IonMonkey, our newest JavaScript JIT, in Firefox. IonMonkey is a huge step forward for JavaScript performance and architecture compiler.