Firefox 48 was released on August 2. It has some quite good features, including a new experimental multiprocess support. Some of the most exciting new features are the following
- Protection against harmful downloads
- GNU/Linux user gain a performance boost with Skia
- Media parser rewritten in Rust language
For details the interested reader is referred to the release notes
Enable multiprocess support
If you got to about:support, you can see, if you have been selected for Multiprocess support - Check for Multiprocess Window 0/1 (Disabled)
You do this at OWN RISK. This is not encouraged at the moment (Especially if you use extensions)
I tried it sucessfully on my Arch Linux Desktop and on my Ubuntu 14.04 Desktop.
In about:config create a new boolean browser.tabs.remote.force-enable value set to true.