Debian and Ubuntu developer Iain Lane writes today on one of the mailing lists of the Ubuntu Linux operating system about the fact that he's been working for the past few weeks on bringing GTK+ 3.20 support to Ubuntu.
According to Iain Lane, the latest GTK+ 3.20 GUI toolkit, which is usually shipped by default with the GNOME 3.20 desktop environment, is ready for upload on the Ubuntu software repositories, for Ubuntu Desktop. Still, he doesn't mention for which Ubuntu version, so we can only guess that he's talking about Ubuntu 16.10.
However, he provides us with a PPA (Personal Package Archive) repository that contains the latest GTK+ 3.20 packages, the Adwaita icon theme, a GTK3 port of Mozilla Firefox 47.0, as well as Baobab and Nautilus 3.20 apps. The PPA is only for Ubuntu 16.10, so do not attempt to install it on Ubuntu 16.04 LTS (Xenial Xerus) because it won't work.
"When I say 'working on,' I really mean that I've been porting the Ubuntu theme, Ambiance, over. This release is a big theme breaker. It's supposed to be the last time this happens, in GTK 3 at least. So my hope is that we're good with theming up to 18.04 LTS now," says Iain Lane in today's mailing list announcement.
Here's how to test GTK 3.20 in Ubuntu 16.10 (Yakkety Yak)
Please try to keep in mind that this announcement is only for Ubuntu developers who maintain GTK apps or theme, to check if things work on their side with these new GTK+ 3.20 builds. Therefore, if you want to test it, open the Terminal app in Ubuntu 16.10 and run the following commands. From our tests, the update breaks the desktop wallpaper.
sudo apt-add-repository ppa:ubuntu-desktop/gtk320
sudo apt update
sudo apt dist-upgrade