Mozilla has released a new beta version of Firefox for Windows, Mac and Linux that adds a number of new features to the popular web browser. Firefox 18 beta includes, among other things, improvements to make JavaScript web apps and games perform more smoothly thanks to a new compiler called IonMonkey.

IonMonkey has been in development for some time now. In layman’s terms, it provides a more efficient way for Firefox to process JavaScript and is able to run new optimizations that simply aren’t possible with JagerMonkey.  It can also quickly emit native code translations of JavaScript functions on ARM, 32-bit and 64-bit architectures.

Download: Firefox 18 Beta (Windows, Mac, Linux)

Those running a Mac will be happy to know that Firefox 18 now supports Apple’s Retina Display. This of course will make virtually everything you do on the web look significantly better on a supporting panel.

There’s also a built-in PDF viewer that works across all platforms and standard support for W3C touch events. Those interested in security features may want to take note that you can now disable insecure content on HTTPS secure websites through the about:config menu.

The full change log has been republished below for your convenience.

  • NEW: Support for Retina Display on OS X 10.7 and up.
  • NEW: Preliminary support for WebRTC.
  • NEW: Built-in PDF viewer.
  • CHANGED: Experience better image quality with our new HTML scaling algorithm.
  • CHANGED: Performance improvements around tab switching.
  • DEVELOPER: CSS3 Flexbox implemented.
  • DEVELOPER: Support for new DOM property window.devicePixelRatio.
  • DEVELOPER: Support for @supports added.
  • DEVELOPER: Improvement in startup time through smart handling of signed extension certificates.
  • HTML5: Support for W3C touch events impemented, taking the place of MozTouch events.
  • FIXED: Disable insecure content loading on HTTPS pages.
  • FIXED: Improved responsiveness for users on proxies.

Interested parties can download the new beta browser by clicking here.