In this article Mahesh Sabnis shows how WPF 3.5 makes use of LINQ to XML.
By now, I assume most of you are well aware of new features on .NET 3.5. Language Integrated Queries (LINQ) is one of the most important features of .NET 3.5. LINQ provides flavours like LINQ to Objects, LINQ to SQL and LINQ to XML. There are lots of advantages of using LINQ to XML, this reduce lots of complexities of XML DOM.