OK - a quick WPF/XAML/MVVM post. Mostly for my own benefit, so I can remember the syntax. This one about a MVVM resource file.
<ResourceDictionary x:Class="FooBar.MVVMResources"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:vm="clr-namespace:foo.ViewModel"
xmlns:vw="clr-namespace:foo.View"
xmlns:vm_common="clr-namespace:bar.ViewModel;assembly=BarAssembly"
xmlns:vw_common="clr-namespace:bar.View;assembly=BarAssembly">
<DataTemplate DataType="{x:Type vm:fooViewModel}">
<vw:fooView/>
</DataTemplate>
<DataTemplate DataType="{x:Type vm_common:barViewModel}">
<vw_common:barView/>
</DataTemplate>
</ResourceDictionary>
As always, feel free to comment, or ask.