Gtk# is a set of .NETbindings for the GTK+GUItoolkit and assorted GNOMElibraries. The library facilitates building graphical GNOME applications using Mono or any other compliant CLR. Gtk# is an event-driven system like any other modern windowing library where every widget allows you to associate handler methods, which get called when particular events happen.
Applications built using Gtk# will run on many platforms including Linux, Windows and OS X. The Mono packages for Windows include GTK+, Gtk# and a native theme to make applications look like native Windows applications. Starting with Mono 1.9, running Gtk# applications on Mac OS X no longer requires the user to run the X11 server.
Glade can be used with the Glade# bindings to easily design GUI applications. A GUI designer called Stetic is integrated with the MonoDevelopIDE.
In addition to support the standard GTK/GNOME stack of development tools, the gtk-dotnet.dll assembly provides a bridge to consume functionality available on the .NET stack. At this point this includes the functionality to use System.Drawing to draw on a widget.