Firefox 4 (free) is now available for your favorite computing platform -- Mac OS X. If you've used the Mozilla browser in the past, you're probably already aware of the update. If not, this is a chance to download and try a laudable Mac browser.
The biggest improvement in Firefox 4 is speed. Although we were unable to perform our own benchmarks, the Firefox website shows that page rendering speeds have improved anywhere from three to six times those of the previous release. The Mozilla engineers also worked in a new layers-based graphics system that takes advantage of OpenGL in Mac OS X for faster performance on graphics-intensive websites. In reality, Firefox still felt slightly slower than Safari in terms of opening and rendering websites, although it feels much faster than previous versions of the browser.
As with previous versions of Firefox, there are numerous plug-ins and add-ons available, as well as "personas" to customize the browser's look and feel. Some plug-ins will need to be updated from earlier versions, requiring a restart of the browser before they'll work properly.
Firefox Sync is a feature that's available to sync your open browser tabs, bookmarks and even passwords between devices. If you install Firefox 4 onto several Macs, like an iMac and a MacBook Air, after closing Firefox on the desktop machine and launching the browser on the laptop you can pick up right where you left off. Regretfully, since there's no Firefox for iPhone or iPad, you can't sync your settings to those devices.
For those who hate downward facing tabs in the tabbed browser interface, you can rejoice in the fact that the new Firefox default puts the tabs on top. If you prefer downward facing tabs, no problem -- you can change the setting. I was glad to see that toolbars are now much more customizable. A control-click lets you add or remove many buttons, including various Google applications or even a print button.
I won't belabor the description of the rest of Firefox 4's new features here. Firefox fans should go out and download the update immediately; the rest of you might want to try out the free browser just to see if the new features are enough to make you switch.