Mozilla has released Firefox 48 for the desktop which includes the long-awaited multi-process feature. Multi-process separates each web tab into its own process. Thus if a web page is crashing or consuming large amount of CPU, the other tabs will remain responsive. This feature has been made available with Safari and Chrome browsers for a while, and has finally made it to Firefox.
Mozilla however is rolling out multi-process feature to all Firefox 48 users in stages over the next few weeks. To find out if your copy of Firefox 48 has it enabled, enter “about:support” on the URL bar.
Look for the entry “Multiprocess Windows” to check if multi-process is enabled. There is no settings to enable this feature yourself, so you just have to wait.