File Under: Browsers

IonMonkey, Retina Support Make for a Faster, Sharper Firefox

Photo: Jim Merithew/Wired

With Firefox 17 out the door, Mozilla is turning its attention to Firefox 18, which is now available in the Firefox beta channel. The focus for this release is speed, with Mozilla set to deliver a new faster JavaScript JIT compiler dubbed IonMonkey.

If you’d like to switch to Firefox’s beta channel, just head over to the beta downloads page.

IonMonkey will replace TraceMonkey and join JagerMonkey as one of the two JIT compilers that make up Firefox’s SpiderMonkey JavaScript engine. Too many monkeys? Here’s the bottom line: Firefox 18 has a faster JIT compiler, which means JavaScript-heavy web apps, games and pages like Gmail should be faster.

If you’d like to know more about the finer points of Firefox’s various JavaScript monkeys, check out this earlier post by Mozilla developer David Mandelin and this series of posts on the Mozilla blog, which get into all the gory details of Firefox’s JavaScript optimization tools.

There are quite a few new features for web developers in this release, including support for the CSS 3 @supports rule I wrote about yesterday. Firefox 18 also supports the latest CSS 3 Flexible Box Model syntax, though it’s disabled, ahem, out of the box. To test out your Flexbox layout in Firefox 18, open up about:config and search for “flexbox.”

Developers working on nice shiny new Mac laptops will be happy to hear that Firefox beta now supports Retina Displays.

The security-conscious have cause to celebrate as well: Firefox 18 has, at long last, landed a setting to disable insecure content on secure websites. It’s off by default since it would probably break a lot of websites (mixing HTTP and HTTPS content on the same page is, sadly, quite common), but if you’d like to give it a try, head to about:config and search for “mixed” which will bring up the relevant options.

For more details on everything that’s new in Firefox beta, be sure to read through Mozilla’s release notes. If you’d rather not use beta-quality software for your everyday browsing, you’ll need to wait until second week of January when Firefox 18 is scheduled to arrive.