Just so that people don't have to do digging in that article. In about:config, set browser.tabs.remote.autostart to true and check about:support for Multiprocess Windows (might need to restart).

For now though you'll have to disable any plugins for it to work which can be a bit of a handicap. But... almost there :).

Please be aware that if you force-enable e10s while using incompatible addons, you'll end up with a very slow browsing experience. http://arewee10syet.com/ has a compatibility list for some of the most popular addons.

Seems like e10s gets disabled if there is a incompatible addon activated.

Not sure I would trust that list, the only two addons I run, is Tree Style Tab and Greasemonkey, both listed as compatible on the website, but going to about:support shows:

> Multiprocess Windows 0/1 (Disabled by add-ons)

Addons are not supported by default in e10s mode on the release channel yet.

What about using incompatible addons triggers a slow browsing experience?

I think it has to do with some kind of global locking/racing conditions.

The current version of LastPass is a big culprit, I've had it lock up nightly for >30s some times. They have a beta version that is e10s compatible which doesn't have this problem.

Got to love the '401 failed fetching from AMO' add on.