GNOME 3.26 Getting Better Half-Tiling Support
Georges Stavracas has been hacking away on better half-tiling support in GNOME Shell / Mutter and is working towards quarter-tiling functionality.
Those interested in tiling windows with GNOME 3.26, you'll want to see Georges' blog post. He's working on "smarter half-tiling" as shown below.
His work stems from this 2011 bug report and is aiming to eventually having a quarter window tiling feature.