Source? I always took XHTML to be an effort to make html into a stricter more parse-friendly format. Xhtml lets you use an xml parser to pull apart a page rather than having to deal with some kind of markup tag soup (which also makes it a great target for tooling within an IDE). XAML is concerned with layouts and binding in ways that, I don&#x27;t believe, were ever intended for Xhtml. I could be wrong but they&#x27;ve always seemed to be worlds apart.