While it was originally scheduled for last week, some last-minute issues preventing the software non-profit organization from releasing it until today.
This version is expected to expand their multi-process support, which separates UI updates from site updates. Typically, Firefox disables the feature with add-ons, because they are given the tools to make decoupling these two spaces… glitchy. Under typical situations, JavaScript and other tasks that run in the page shouldn’t affect the browser’s interface. You can see how this could be a problem if, for instance, an add-on loops between tasks on both at the same time. As such, Mozilla is pulling access to a few APIs when multi-process is enabled.
With Firefox 49, VentureBeat is reporting that Mozilla is allowing a “small initial set of compatible add-ons” to be enabled alongside multi-process. If you don’t have any non-compatible add-ons installed, then you should see Multiprocess Windows enabled in about:support. Otherwise, it will be disabled and you won’t see any difference.
Interestingly, Mozilla is promoting “Refresh Firefox” at their site if you have the latest version. This basically cleans all the add-ons out of your user profile, but maintains browsing history, bookmarks, and the like. It might have been around for a while, but, if it’s new, it times nicely with the multi-process rollout. On top of cleaning out old, crufty add-ons, a user should see a bigger jump when Mozilla’s enhancements are (I’m guessing) enabled.
Mozilla has also changed a few things here and there, too. While many of our readers will probably have hardware acceleration for video, they have just added in SSSE3 enhancements if GPU support isn’t available. I’m not sure all of the use cases for this, but we do expect it would help in virtualized environments and certain, older PCs (ex: Intel Atom we are looking at you).
