wpf-notifyicon/Source/Windowless Sample/MainWindow.xaml

<Window x:Class="Windowless_Sample.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <TextBlock Text="Have a look at App.xaml and App.xaml.cs to see how things are working" />
    </Grid>
</Window>