Hi Louis Bouchard,
You can extract whatever you want in a loose xaml file as a ResourceDictionary and then you can refer to this xaml file in your actual ResourceDictionary via the Source property. For more information read this
On a side note, I'd like to inform you that we've just released an online tool that allows you to reduce the size of your Silverilght applications. For more information, please visit http://blogs.telerik.com/blogs/posts/10-06-10/telerik_assembly_minifier.aspx
the Telerik team
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