On Tue, Apr 12, 2016 at 3:17 PM, Ryan Lerch <rlerch@redhat.com> wrote:

I noticed that there is an upcoming firefox release, with quite an interesting item in the Beta notes[1], which is probably worth writing up a post in the magazine for similar to ones we have done in the past[2][3].

* GTK3 integration (GNU/Linux only)

Does anyone know exactly what this GTK3 integration is?

It means Firefox uses gtk3 instead of gtk2.
Firefox in Fedora has been using gtk3 for a while now (since 2014, according to the rpm changelog), and this specific upstream release note item you mentioned here is about Mozilla's official builds, which is different than what we ship in Fedora.

-Elad.