Firefox 48 Release Notes
Big news from Mozilla this week: With Firefox 48, the multi-process engine e10s is now enabled for many users, making Firefox much more robust, faster and more reliable. Also, protection against harmful downloads has been improved and unsigned/unverified add-ons won’t load anymore. Web Extensions support including CSP enforcements for web extensions is also new, just like the
about:debugging developer page. For developers, the DevTools come with an improved font inspector,
calc() is now supported for
line-heightand can be nested, and, last but not least, support for the CSP directive
upgrade-insecure-requests has been added.