Mozilla Lays Out Long Term Firefox Multi-Process Plans

Ever since the rise of multiple tabs in a browser, the logical extension has been to adopt multiple processes as well. Since 2009, both Internet Explorer and Chrome adopted this strategy, separating the browser frame from the rendering engine for each tab(s). At the same time, Mozilla announced plans to do the same. After a long wait, Firefox has recently adopted multi-process but the  work is not done yet.

Due to the way the browser is designed and run, the browser had a harder than its competitors in moving to multi-process. One major change that had to be made was to the extension engine which was adopted in 2015. Since then, Firefox 48 and 49 have slowly rolled out multi-process to users. Firefox 50 finally brings it to all users with compatible extensions. Mozilla is already claiming a 400% improvement in responsiveness, a figure that jumps to 700% during page loads.

Moving forward, Firefox 51 is expected to bring multi-process to everything except incompatible extensions. The next step to spin off a second content process, with more being planned until the point of diminishing returns. Work is also being done on a new security sandbox. While it is still pretty loose and only added for Windows, work is being done to harden it and expand it to Linux and Mac. With each process within its own sandbox, attacking Firefox users will become much harder.

With all of these improvements in mind, I suspect Firefox may see a resurgence in adoption. Chrome has gained market share in recent years, mostly at the expense of Firefox. With the march to feature parity, performance. and security, many may choose to migrate back, especially since Chrome is now synonymous with memory leaks.