Gtk# is a Graphical User Interface Toolkit for mono and .Net. The
project binds the gtk+ toolkit and assorted GNOME libraries, enabling
fully native graphical Gnome application development using Mono and
.Net development frameworks.

Upstream has not had updates since 2014, so this is using a well-
maintained fork by the GLibSharp team.

This is able to be installed alongside gtk-sharp without conflicts.