XamlT is an easy to install tool which will help Silverlight 1.0, Silverlight 1.1, Workflow Foundation (WF) and WPF users who are trying to understand the Xaml Vocabularies that are available.

The primary view is to look at the type hierarchy and the content model, properties (normal and attachable) defined on each type (click on image for a marked up example of viewing the Panel classes in WPF):
  

The type representations are like navigable hyperlinks and it all runs in an IE like Shell with support for ctrl-click (new tab), shift-click (new window) and just normal click.

Once you find a type you like, click on the SDK button in the partially transparent toolbar in the top right of the type display and it will switch over to an integrated MSDN viewer.

It also contains a tool that can convert from Xaml to C# that I've been working on.

Run XamlT via a click-once install. (.application)

http://XamlT.com/Blog shows you the latest blog posts about XamlT.

http://XamlT.com/ToDo shows you my list for issues to fix or build into XamlT. Really should set up a wiki for this.