<ThreadSafetyStatement>Gtk# is thread aware, but not thread safe; See the <linklocation="node:gtk-sharp/programming/threads">Gtk# Thread Programming</link> for details.</ThreadSafetyStatement>
A <seecref="T:Gtk.Window"/> can be one of these types.
Most things you would consider a "window" should have type <seecref="T:Gtk.WindowType.TopLevel"/> ;
windows with this type are managed by the window manager and have a frame by default (call <seecref="P:Gtk.Window.Decorated"/> to toggle the frame).
Windows with type <seecref="T:Gtk.Window.Popup"/> are ignored by the window manager;
window manager keybindings will not work on them, the window manager will not decorate the window with a frame, many GTK+ features that rely on the window manager will not work (e.g. resize grips and maximization/minimization).</para>
<para>
<seecref="T:Gtk.WindowType.Popup"/> is used to implement widgets such as <seecref="T:Gtk.Menu"/> or tooltips that you normally do not think of as windows per se. Nearly all windows should be <seecref="T:Gtk.Window.Toplevel"/>. In particular, do not use <seecref="T:Gtk.Window.Popup"/> just to turn off the window borders; use <seecref="P:Gtk.Window.Decorated"/> for instead.</para>