Introducing Site Isolation in Firefox (Mozilla security blog)

The Mozilla Security Blog announces
that there is a new site-isolation mechanism available for testing in the
Firefox browser. It's a defense against Meltdown and Spectre exploits.

This fundamental redesign of Firefox's Security architecture extends
current security mechanisms by creating operating system process-level
boundaries for all sites loaded in Firefox for Desktop. Isolating each site
into a separate operating system process makes it even harder for malicious
sites to read another site’s secret or private data.