GNOME Boxes has been out for over two years but in a world where virt-manager already does a fantastic job for desktop-based, open-source, Linux virtualization management, the GNOME application doesn't seem to receive too much widespread attention for Linux desktop virtualization. Regardless, during the GNOME 3.12 development cycle the Boxes app received new features. In my personal use of GNOME Boxes, I found it very easy-to-use and that was its main benefit, while the rest of the time I am using virt-manager when not running VirtualBox or VMware's products.
GNOME Boxes 3.12 drops its use of Clutter in favor of just using the GTK+ tool-kit, supoports importing existing virtual machines from the system libvirt, and can now handle NAT networking support.
Some of the improvements planned for GNOME Boxes 3.14 include import/export support of VMs, express installation support for more operating systems and Linux distributions, supporting multiple monitors in VMs, snapshot support, and automatic downloading of ISOs and images.
Those interested in learning more about the latest work on GNOME Boxes can read this blog post by developer Zeeshan Ali Khattak.